WikiVet English - User contributions [en]

WikiPath

2007-11-20T15:43:48Z

Mayazoey:

<big>''[[Acknowledgements]]''</big>

<big>'''[[Wikipath Guidelines]]'''</big>

<big>'''[[General Pathology]]'''</big>

<big>'''[[Alimentary - includes liver and pancreas|Alimentary System (including Liver and Pancreas)]]'''</big>

<big>'''[[Respiratory system|Respiratory System]]'''</big>

<big>'''[[Cardiovascular system|Cardiovascular System]]'''</big>

<big>'''[[Nervous System]]'''</big>

<big>'''[[Endocrine]]'''</big>

<big>'''[[Urinary System]]'''</big>

<big>'''[[Musculoskeletal]]'''</big>

[[Lymphoreticular/Haemotopoietic System|Lymphoreticular/Haemotopoietic System]]

[[Integumentary - includes mammary]]

[[Reproductive]]

[[Special senses]]

<big>'''[[Infectious agents and parasites]]'''</big>

[[Toxicological Pathology]]

[[Clinical Pathology]]

==Wiki Vet Learning Environment==
Patent Pending :oP

<big>
'''[[Flashcard Main Page|Flashcards]]'''

'''[[Concept Maps]]

'''[[Case Studies]]'''

'''[[Personal Experiences]]'''

'''[[Postgraduate / Certificate Material]]'''</big>

Please see [http://meta.wikipedia.org/wiki/MediaWiki_i18n documentation on customizing the interface]
and the [http://meta.wikipedia.org/wiki/MediaWiki_User%27s_Guide User's Guide] for usage and configuration help.

WikiPath

2007-11-20T15:43:33Z

Mayazoey:

Sarah McFarland

2007-10-09T19:58:57Z

Mayazoey: /* Day one thoughts */

Sarah McFarland
== About me ==

4th year veterinary student at the University of Edinburgh. e-mail: [mailto:s0454676@sms.ed.ac.uk s0454676@sms.ed.ac.uk]

[[Image:Funny_cats.jpg|250px]]]]

== What I hope to get out of this project ==

To become more technologically savvy and get the chance to work with a group in creating something new and forward thinking.

== My best learning experience ==

Have learned from all sorts of experiences, don't think its as simple as narrowing it down to one.

== Pathology that interests me ==
endocrine and cardiopathology

== Pathology that is difficult ==
histopathology... the best analysis i can usually come up with is wow, this looks pretty...

== Day one thoughts ==
'''What (three things) I learnt today''' 
#about the concept of liminoid (spelling?)
#how it is valuable when different institutions get together to share perspectives and ideas
#how i need to catch up with the cyber world
'''What I still need to learn''' 
how to use all these fancy symbols! 
'''How I feel about what has happened today''' 
enjoyed today and looking forward to help creating a useful learning resource

==Three weeks into the wikivet project (or thereabouts)==

===Sections I've been working on===
* [[The Small and Large Intestines]]
* [[Urinary System]]

===What I feel I've gained so far from being involved in the project===
* some much needed pathology revision!
* a better knowledge of pathology resources out there
* frustration from the fact that i still can't figure out how to get the third symbol on some of my computer keys to show up!

===Problems or issues that I've had or can forsee===
* its going to be a big challenge to standardise all of the information and try to have everyone's work in a similar format and including a similar amount of detail
* making it something students are motivated and keen to use as a learning resource, i.e. something that offers more than just another set of notes to trudge through
* editing issues if all students get access to editing

===My suggestions for improving the way the project works for the future===
* having a rough set of guidelines in place for the format of sections
* assigning some people solely to the role of proofreading and editing would be really helpful as there would be a chain of checks and balances that way
* again, this has to do with delineating tasks. think it would be nice to have some people just work on more creative things such as quizzes,games, interesting case studies, mind maps, etc that give a more problem solving approach to learning

===What involvement (if any!) I would like to have with the project in the future===
* hope to be able to stay involved with the project as it evolves
* would like to be involved in developing a section dedicated to case studies, problems solving, quizzes, etc.
* also would like to help out with creating an exotics section

File:Amyloidosis histology.jpg

2007-10-07T17:05:07Z

Mayazoey: Supplied by Susan Rhind, University of Edinburgh

Supplied by Susan Rhind, University of Edinburgh

File:Picture1.png

2007-09-07T13:45:11Z

Mayazoey:

File:Cambridge comparative.jpg

2007-09-07T13:43:19Z

Mayazoey: Comparative kidneys; Courtesy of University of Cambridge

Comparative kidneys; Courtesy of University of Cambridge

File:Comparative kidneys; cambridge.jpg

2007-09-07T13:22:40Z

Mayazoey: Cambridge urinary lectures.

Cambridge urinary lectures.

Sarah McFarland

2007-08-30T10:00:59Z

Mayazoey: /* What involvement (if any!) I would like to have with the project in the future */

Sarah McFarland
== About me ==

4th year veterinary student at the University of Edinburgh. e-mail: [mailto:s0454676@sms.ed.ac.uk s0454676@sms.ed.ac.uk]

[[Image:Funny_cats.jpg|250px]]]]

== What I hope to get out of this project ==

To become more technologically savvy and get the chance to work with a group in creating something new and forward thinking.

== My best learning experience ==

Have learned from all sorts of experiences, don't think its as simple as narrowing it down to one.

== Pathology that interests me ==
endocrine and cardiopathology

== Pathology that is difficult ==
histopathology... the best analysis i can usually come up with is wow, this looks pretty...

== Day one thoughts ==
'''What (three things) I learnt today''' 
#about the concept of liminoid (spelling?)
#how it is valuable when different instituions get together to share perspectives and ideas
#how i need to catch up with the cyber world
'''What I still need to learn''' 
how to use all these fancy symbols! 
'''How I feel about what has happened today''' 
enjoyed today and looking forward to help creating a useful learning resource

==Three weeks into the wikivet project (or thereabouts)==

===Sections I've been working on===
* [[The Small and Large Intestines]]
* [[Urinary System]]

===What I feel I've gained so far from being involved in the project===
* some much needed pathology revision!
* a better knowledge of pathology resources out there
* frustration from the fact that i still can't figure out how to get the third symbol on some of my computer keys to show up!

===Problems or issues that I've had or can forsee===
* its going to be a big challenge to standardise all of the information and try to have everyone's work in a similar format and including a similar amount of detail
* making it something students are motivated and keen to use as a learning resource, i.e. something that offers more than just another set of notes to trudge through
* editing issues if all students get access to editing

===My suggestions for improving the way the project works for the future===
* having a rough set of guidelines in place for the format of sections
* assigning some people solely to the role of proofreading and editing would be really helpful as there would be a chain of checks and balances that way
* again, this has to do with delineating tasks. think it would be nice to have some people just work on more creative things such as quizzes,games, interesting case studies, mind maps, etc that give a more problem solving approach to learning

===What involvement (if any!) I would like to have with the project in the future===
* hope to be able to stay involved with the project as it evolves
* would like to be involved in developing a section dedicated to case studies, problems solving, quizzes, etc.
* also would like to help out with creating an exotics section

Sarah McFarland

2007-08-30T09:59:20Z

Mayazoey: /* What involvement (if any!) I would like to have with the project in the future */

Sarah McFarland
== About me ==

4th year veterinary student at the University of Edinburgh. e-mail: [mailto:s0454676@sms.ed.ac.uk s0454676@sms.ed.ac.uk]

[[Image:Funny_cats.jpg|250px]]]]

== What I hope to get out of this project ==

To become more technologically savvy and get the chance to work with a group in creating something new and forward thinking.

== My best learning experience ==

Have learned from all sorts of experiences, don't think its as simple as narrowing it down to one.

== Pathology that interests me ==
endocrine and cardiopathology

== Pathology that is difficult ==
histopathology... the best analysis i can usually come up with is wow, this looks pretty...

== Day one thoughts ==
'''What (three things) I learnt today''' 
#about the concept of liminoid (spelling?)
#how it is valuable when different instituions get together to share perspectives and ideas
#how i need to catch up with the cyber world
'''What I still need to learn''' 
how to use all these fancy symbols! 
'''How I feel about what has happened today''' 
enjoyed today and looking forward to help creating a useful learning resource

==Three weeks into the wikivet project (or thereabouts)==

===Sections I've been working on===
* [[The Small and Large Intestines]]
* [[Urinary System]]

===What I feel I've gained so far from being involved in the project===
* some much needed pathology revision!
* a better knowledge of pathology resources out there
* frustration from the fact that i still can't figure out how to get the third symbol on some of my computer keys to show up!

===Problems or issues that I've had or can forsee===
* its going to be a big challenge to standardise all of the information and try to have everyone's work in a similar format and including a similar amount of detail
* making it something students are motivated and keen to use as a learning resource, i.e. something that offers more than just another set of notes to trudge through
* editing issues if all students get access to editing

===My suggestions for improving the way the project works for the future===
* having a rough set of guidelines in place for the format of sections
* assigning some people solely to the role of proofreading and editing would be really helpful as there would be a chain of checks and balances that way
* again, this has to do with delineating tasks. think it would be nice to have some people just work on more creative things such as quizzes,games, interesting case studies, mind maps, etc that give a more problem solving approach to learning

===What involvement (if any!) I would like to have with the project in the future===
* hope to be able to stay involved with the project as it evolves
* would like to be involved in developing a section dedicated to case studies, problems solving, quizzes, etc.

Sarah McFarland

2007-08-30T09:58:40Z

Mayazoey: /* What involvement (if any!) I would like to have with the project in the future */

Sarah McFarland
== About me ==

4th year veterinary student at the University of Edinburgh. e-mail: [mailto:s0454676@sms.ed.ac.uk s0454676@sms.ed.ac.uk]

[[Image:Funny_cats.jpg|250px]]]]

== What I hope to get out of this project ==

To become more technologically savvy and get the chance to work with a group in creating something new and forward thinking.

== My best learning experience ==

Have learned from all sorts of experiences, don't think its as simple as narrowing it down to one.

== Pathology that interests me ==
endocrine and cardiopathology

== Pathology that is difficult ==
histopathology... the best analysis i can usually come up with is wow, this looks pretty...

== Day one thoughts ==
'''What (three things) I learnt today''' 
#about the concept of liminoid (spelling?)
#how it is valuable when different instituions get together to share perspectives and ideas
#how i need to catch up with the cyber world
'''What I still need to learn''' 
how to use all these fancy symbols! 
'''How I feel about what has happened today''' 
enjoyed today and looking forward to help creating a useful learning resource

==Three weeks into the wikivet project (or thereabouts)==

===Sections I've been working on===
* [[The Small and Large Intestines]]
* [[Urinary System]]

===What I feel I've gained so far from being involved in the project===
* some much needed pathology revision!
* a better knowledge of pathology resources out there
* frustration from the fact that i still can't figure out how to get the third symbol on some of my computer keys to show up!

===Problems or issues that I've had or can forsee===
* its going to be a big challenge to standardise all of the information and try to have everyone's work in a similar format and including a similar amount of detail
* making it something students are motivated and keen to use as a learning resource, i.e. something that offers more than just another set of notes to trudge through
* editing issues if all students get access to editing

===My suggestions for improving the way the project works for the future===
* having a rough set of guidelines in place for the format of sections
* assigning some people solely to the role of proofreading and editing would be really helpful as there would be a chain of checks and balances that way
* again, this has to do with delineating tasks. think it would be nice to have some people just work on more creative things such as quizzes,games, interesting case studies, mind maps, etc that give a more problem solving approach to learning

===What involvement (if any!) I would like to have with the project in the future===
* hope to be able to stay involved with the project as it evolves
* would like to be involoved in developing a section dedicated to case studies, problems solving, quizzes, etc.

Sarah McFarland

2007-08-30T09:56:37Z

Mayazoey: /* My suggestions for improving the way the project works for the future */

Sarah McFarland
== About me ==

4th year veterinary student at the University of Edinburgh. e-mail: [mailto:s0454676@sms.ed.ac.uk s0454676@sms.ed.ac.uk]

[[Image:Funny_cats.jpg|250px]]]]

== What I hope to get out of this project ==

To become more technologically savvy and get the chance to work with a group in creating something new and forward thinking.

== My best learning experience ==

Have learned from all sorts of experiences, don't think its as simple as narrowing it down to one.

== Pathology that interests me ==
endocrine and cardiopathology

== Pathology that is difficult ==
histopathology... the best analysis i can usually come up with is wow, this looks pretty...

== Day one thoughts ==
'''What (three things) I learnt today''' 
#about the concept of liminoid (spelling?)
#how it is valuable when different instituions get together to share perspectives and ideas
#how i need to catch up with the cyber world
'''What I still need to learn''' 
how to use all these fancy symbols! 
'''How I feel about what has happened today''' 
enjoyed today and looking forward to help creating a useful learning resource

==Three weeks into the wikivet project (or thereabouts)==

===Sections I've been working on===
* [[The Small and Large Intestines]]
* [[Urinary System]]

===What I feel I've gained so far from being involved in the project===
* some much needed pathology revision!
* a better knowledge of pathology resources out there
* frustration from the fact that i still can't figure out how to get the third symbol on some of my computer keys to show up!

===Problems or issues that I've had or can forsee===
* its going to be a big challenge to standardise all of the information and try to have everyone's work in a similar format and including a similar amount of detail
* making it something students are motivated and keen to use as a learning resource, i.e. something that offers more than just another set of notes to trudge through
* editing issues if all students get access to editing

===My suggestions for improving the way the project works for the future===
* having a rough set of guidelines in place for the format of sections
* assigning some people solely to the role of proofreading and editing would be really helpful as there would be a chain of checks and balances that way
* again, this has to do with delineating tasks. think it would be nice to have some people just work on more creative things such as quizzes,games, interesting case studies, mind maps, etc that give a more problem solving approach to learning

===What involvement (if any!) I would like to have with the project in the future===
*
*
*

Sarah McFarland

2007-08-30T09:49:34Z

Mayazoey: /* Problems or issues that I've had or can forsee */

Sarah McFarland
== About me ==

4th year veterinary student at the University of Edinburgh. e-mail: [mailto:s0454676@sms.ed.ac.uk s0454676@sms.ed.ac.uk]

[[Image:Funny_cats.jpg|250px]]]]

== What I hope to get out of this project ==

To become more technologically savvy and get the chance to work with a group in creating something new and forward thinking.

== My best learning experience ==

Have learned from all sorts of experiences, don't think its as simple as narrowing it down to one.

== Pathology that interests me ==
endocrine and cardiopathology

== Pathology that is difficult ==
histopathology... the best analysis i can usually come up with is wow, this looks pretty...

== Day one thoughts ==
'''What (three things) I learnt today''' 
#about the concept of liminoid (spelling?)
#how it is valuable when different instituions get together to share perspectives and ideas
#how i need to catch up with the cyber world
'''What I still need to learn''' 
how to use all these fancy symbols! 
'''How I feel about what has happened today''' 
enjoyed today and looking forward to help creating a useful learning resource

==Three weeks into the wikivet project (or thereabouts)==

===Sections I've been working on===
* [[The Small and Large Intestines]]
* [[Urinary System]]

===What I feel I've gained so far from being involved in the project===
* some much needed pathology revision!
* a better knowledge of pathology resources out there
* frustration from the fact that i still can't figure out how to get the third symbol on some of my computer keys to show up!

===Problems or issues that I've had or can forsee===
* its going to be a big challenge to standardise all of the information and try to have everyone's work in a similar format and including a similar amount of detail
* making it something students are motivated and keen to use as a learning resource, i.e. something that offers more than just another set of notes to trudge through
* editing issues if all students get access to editing

===My suggestions for improving the way the project works for the future===
*
*
*

===What involvement (if any!) I would like to have with the project in the future===
*
*
*

Sarah McFarland

2007-08-30T09:35:17Z

Mayazoey: /* What I feel I've gained so far from being involved in the project */

Sarah McFarland

2007-08-30T09:35:01Z

Mayazoey: /* What I feel I've gained so far from being involved in the project */

Sarah McFarland

2007-08-30T09:32:30Z

Mayazoey: /* Three weeks into the wikivet project (or thereabouts) */

Sarah McFarland

2007-08-30T09:32:07Z

Mayazoey: /* Sections I've been working on */

WikiPath

2007-08-29T10:35:16Z

Mayazoey:

<big>'''[[General Pathology]]'''</big>

<big>'''[[Alimentary - includes liver and pancreas|Alimentary System (including Liver and Pancreas)]]'''</big>

<big>'''[[Respiratory system|Respiratory System]]'''</big>

<big>'''[[Cardiovascular system]]'''</big>

<big>'''[[Nervous System]]'''</big>

<big>'''[[Endocrine]]'''</big>

[[Lymphoreticular/Haemotopoietic system]]

[[Integumentary - includes mammary]]

<big>'''[[Urinary System]]'''<big/big>

[[Musculoskeletal]]

[[Reproductive]]

[[Special senses]]

<big>'''[[Infectious agents and parasites]]'''</big>

[[Toxicological Pathology]]

[[Clinical Pathology]]

==Wiki Vet Learning Environment==
Patent Pending :oP

<big>
'''[[Flashcard Main Page|Flashcards]]'''

'''[[Concept Maps]]

'''[[Case Studies]]'''

'''[[Personal Experiences]]'''

'''[[Postgraduate / Certificate Material]]'''</big>

Please see [http://meta.wikipedia.org/wiki/MediaWiki_i18n documentation on customizing the interface]
and the [http://meta.wikipedia.org/wiki/MediaWiki_User%27s_Guide User's Guide] for usage and configuration help.

WikiPath

2007-08-29T10:31:14Z

Mayazoey:

<big>'''[[General Pathology]]'''</big>

<big>'''[[Alimentary - includes liver and pancreas|Alimentary System (including Liver and Pancreas)]]'''</big>

<big>'''[[Respiratory system|Respiratory System]]'''</big>

<big>'''[[Cardiovascular system]]'''</big>

<big>'''[[Nervous System]]'''</big>

<big>'''[[Endocrine]]'''</big>

[[Lymphoreticular/Haemotopoietic system]]

[[Integumentary - includes mammary]]

<big>'''[[Urinary]]'''<big/big>

[[Musculoskeletal]]

[[Reproductive]]

[[Special senses]]

<big>'''[[Infectious agents and parasites]]'''</big>

[[Toxicological Pathology]]

[[Clinical Pathology]]

==Wiki Vet Learning Environment==
Patent Pending :oP

<big>
'''[[Flashcard Main Page|Flashcards]]'''

'''[[Concept Maps]]

'''[[Case Studies]]'''

'''[[Personal Experiences]]'''

'''[[Postgraduate / Certificate Material]]'''</big>

Please see [http://meta.wikipedia.org/wiki/MediaWiki_i18n documentation on customizing the interface]
and the [http://meta.wikipedia.org/wiki/MediaWiki_User%27s_Guide User's Guide] for usage and configuration help.

WikiPath

2007-08-29T10:30:56Z

Mayazoey:

<big>'''[[General Pathology]]'''</big>

<big>'''[[Alimentary - includes liver and pancreas|Alimentary System (including Liver and Pancreas)]]'''</big>

<big>'''[[Respiratory system|Respiratory System]]'''</big>

<big>'''[[Cardiovascular system]]'''</big>

<big>'''[[Nervous System]]'''</big>

<big>'''[[Endocrine]]'''</big>

[[Lymphoreticular/Haemotopoietic system]]

[[Integumentary - includes mammary]]

<big>'''[[Urinary]]'''

[[Musculoskeletal]]

[[Reproductive]]

[[Special senses]]

<big>'''[[Infectious agents and parasites]]'''</big>

[[Toxicological Pathology]]

[[Clinical Pathology]]

==Wiki Vet Learning Environment==
Patent Pending :oP

<big>
'''[[Flashcard Main Page|Flashcards]]'''

'''[[Concept Maps]]

'''[[Case Studies]]'''

'''[[Personal Experiences]]'''

'''[[Postgraduate / Certificate Material]]'''</big>

Please see [http://meta.wikipedia.org/wiki/MediaWiki_i18n documentation on customizing the interface]
and the [http://meta.wikipedia.org/wiki/MediaWiki_User%27s_Guide User's Guide] for usage and configuration help.

User:Mayazoey

2007-08-28T15:26:08Z

Mayazoey:

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

==Introduction to the Intestines==

=== Basic Anatomy and Physiology ===

The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===

'''Secretions'''

*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

'''Epithelium'''

*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.

'''Commensal flora'''

*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).

'''Movement'''

*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.

'''Cell-mediated and humoural defences'''

*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).

=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a small amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which relies heavily on the end products of microbial digestion from the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach (Reece, 2005).

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livingstone, London, England, 2000.

==Contents==

===[[Intestines - developmental|Developmental Anomalies]]===

===[[Physical disturbances]]===

===[[Intestines - Vascular Disturbances|Vascular Disturbances]]===

===[[Intestines - Proliferative Pathology|Proliferative Pathology]]===

===[[Intestines - Inflammation|Inflammatory Pathology]]===

===[[Diarrhoea]]===

===[[Parasites]]===

===[[Diseases due to pathogens]]===

===[[Diseases in animal species]]===

===[[Clinical Pathology]]===

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction, pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses greater than 4 years of age. Typically, they lodge at the pelvic flexure or the transverse colon.

====== Impaction ======
Impaction of the colon can occur in all species.
*In the dog and cat, dehydrated faecal material is the main cause of impaction.
*In the horse, faeces, digesta, sand, or fibrous material can all contribute to impaction Predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility.
*Antihelminthic administration or large parasite burdens can also lead to impaction.

====== Extrinsic ======
Obstruction of the intestine due to external factors such as tumours, abscesses, and fibrous adhesions is a common occurrence.
*Neoplasia in structures adjacent to the intestines can spread and cause external compression. Pancreatic tumours in particular can extend and impinge on the duodenum.
*Inflammatory adhesions, following gut perforation, peritonitis or surgery, consist of fibrous tissue bands that may restrict intestinal motility and cause kinks in the mesentery.
*Pedicles of tumours such as lipomas in horses can become wound in loops of intestine leading to obstruction and possible strangulation.
*Prostatic enlargement in the dog can lead to compression of the rectum.

===== Functional =====
*Paralytic ileus is a common condition that can occur following trauma or abdominal surgery. Intestinal stasis leads to distension with gas and fluid as well as a flaccid intestinal wall.
*Dysautonomia is a condition that most notably affects horses and cats.
**Equine dysautonomia (grass sickness) occurs mostly in the UK and western Europe. ''Clostridium botulinum'' is thought to be implicated although the exact cause is still unknown. Affected animals are dull, restless, show signs of colic, and in acute cases become severly tympanic, avoid swallowing and salivate excessively. Degenerative lesions are seen in the autonomic nerve ganglia, including enteric plexuses.
**Feline dysautonomia (Key-Gaskell syndrome) occurs mostly in the UK and continental Europe. It is also of unknown aetiology although environmental toxins, infectious agents and botulinum toxins have been suggested as causative factors. Clinical signs include anorexia, depression, bradycardia, decreased lacrimation, altered pupillary dilataion, megaoesphagus and constipation. As in equine dysautonomia, degenerative lesions of autonomic nerve ganglia can be seen.

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-28T11:59:23Z

Mayazoey:

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

==Introduction to the Intestines==

=== Basic Anatomy and Physiology ===

The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===

'''Secretions'''

*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

'''Epithelium'''

*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.

'''Commensal flora'''

*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).

'''Movement'''

*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.

'''Cell-mediated and humoural defences'''

*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).

=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a small amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which relies heavily on the end products of microbial digestion from the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach (Reece, 2005).

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livingstone, London, England, 2000.

==Contents==

===[[Intestines - developmental|Developmental Anomalies]]===

===[[Physical disturbances]]===

===[[Intestines - Vascular Disturbances|Vascular Disturbances]]===

===[[Intestines - Proliferative Pathology|Proliferative Pathology]]===

===[[Intestines - Inflammation|Inflammatory Pathology]]===

===[[Diarrhoea]]===

===[[Parasites]]===

===[[Diseases due to pathogens]]===

===[[Diseases in animal species]]===

===[[Clinical Pathology]]===

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction, pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses greater than 4 years of age. Typically, they lodge at the pelvic flexure or the transverse colon.

====== Impaction ======
Impaction of the colon can occur in all species.
*In the dog and cat, dehydrated faecal material is the main cause of impaction.
*In the horse, faeces, digesta, sand, or fibrous material can all contribute to impaction Predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility.
*Antihelminthic administration or large parasite burdens can also lead to impaction.

====== Extrinsic ======
Obstruction of the intestine due to external factors such as tumours, abscesses, and fibrous adhesions is a common occurrence.
*Neoplasia in structures adjacent to the intestines can spread and cause external compression. Pancreatic tumours in particular can extend and impinge on the duodenum.
*Inflammatory adhesions, following gut perforation, peritonitis or surgery, consist of fibrous tissue bands that may restrict intestinal motility and cause kinks in the mesentery.
*Pedicles of tumours such as lipomas in horses can become wound in loops of intestine leading to obstruction and possible strangulation.
*Prostatic enlargement in the dog can lead to compression of the rectum.

===== Functional =====
*Paralytic ileus is a common condition that can occur following trauma or abdominal surgery. Intestinal stasis leads to distension with gas and fluid as well as a flaccid intestinal wall.
*Dysautonomia is a condition that most notably affects horses and cats.
**Equine dysautonomia (grass sickness) occurs mostly in the UK and western Europe. ''Clostridium botulinum'' is thought to be implicated although the exact cause is still unknown. Affected animals are dull, restless, show signs of colic, and in acute cases become severly tympanic, avoid swallowing and salivate excessively. Degenerative lesions are seen in the autonomic nerve ganglia, including enteric plexuses.
**Feline dysautonomia (Key-Gaskell syndrome) occurs mostly in the UK and continental Europe. It is also of unknown aetiology although environmental toxins, infectious agents and botulinum toxins have been suggested as causative factors. Clinical signs include anorexia, depression, bradycardia, decreased lacrimation, altered pupillary dilataion, megaoesphagus and constipation. As in equine dysautonomia, degenerative lesions of autonomic nerve ganglia can be seen.

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

File:Large colon torsion horse.jpg

2007-08-28T09:31:30Z

Mayazoey: Large colon torsion in the horse. Courtesy of Elspeth Milne, University of Edinburgh.

Large colon torsion in the horse. Courtesy of Elspeth Milne, University of Edinburgh.

File:Colon adhesions horse.jpg

2007-08-28T09:23:58Z

Mayazoey: Colonic adhesions in the horse. Courtesy of Elspeth Milne, University of Edinburgh.

Colonic adhesions in the horse. Courtesy of Elspeth Milne, University of Edinburgh.

File:Pedunc lipoma closeup.jpg

2007-08-28T09:07:38Z

Mayazoey:

Sarah McFarland

2007-08-27T08:37:40Z

Mayazoey:

Sarah McFarland

2007-08-27T08:37:32Z

Mayazoey:

Sarah McFarland

2007-08-27T08:35:20Z

Mayazoey:

Sarah McFarland

2007-08-27T08:34:05Z

Mayazoey: /* About me */

User:Mayazoey

2007-08-11T14:42:32Z

Mayazoey:

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction, pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses greater than 4 years of age. Typically, they lodge at the pelvic flexure or the transverse colon.

====== Impaction ======
Impaction of the colon can occur in all species.
*In the dog and cat, dehydrated faecal material is the main cause of impaction.
*In the horse, faeces, digesta, sand, or fibrous material can all contribute to impaction Predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility.
*Antihelminthic administration or large parasite burdens can also lead to impaction.

====== Extrinsic ======
Obstruction of the intestine due to external factors such as tumours, abscesses, and fibrous adhesions is a common occurrence.
*Neoplasia in structures adjacent to the intestines can spread and cause external compression. Pancreatic tumours in particular can extend and impinge on the duodenum.
*Inflammatory adhesions, following gut perforation, peritonitis or surgery, consist of fibrous tissue bands that may restrict intestinal motility and cause kinks in the mesentery.
*Pedicles of tumours such as lipomas in horses can become wound in loops of intestine leading to obstruction and possible strangulation.
*Prostatic enlargement in the dog can lead to compression of the rectum.

===== Functional =====
*Paralytic ileus is a common condition that can occur following trauma or abdominal surgery. Intestinal stasis leads to distension with gas and fluid as well as a flaccid intestinal wall.
*Dysautonomia is a condition that most notably affects horses and cats.
**Equine dysautonomia (grass sickness) occurs mostly in the UK and western Europe. ''Clostridium botulinum'' is thought to be implicated although the exact cause is still unknown. Affected animals are dull, restless, show signs of colic, and in acute cases become severly tympanic, avoid swallowing and salivate excessively. Degenerative lesions are seen in the autonomic nerve ganglia, including enteric plexuses.
**Feline dysautonomia (Key-Gaskell syndrome) occurs mostly in the UK and continental Europe. It is also of unknown aetiology although environmental toxins, infectious agents and botulinum toxins have been suggested as causative factors. Clinical signs include anorexia, depression, bradycardia, decreased lacrimation, altered pupillary dilataion, megaoesphagus and constipation. As in equine dysautonomia, degenerative lesions of autonomic nerve ganglia can be seen.

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-11T14:18:13Z

Mayazoey:

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction, pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses greater than 4 years of age. Typically, they lodge at the pelvic flexure or the transverse colon.

====== Impaction ======
Impaction of the colon can occur in all species.
*In the dog and cat, dehydrated faecal material is the main cause of impaction.
*In the horse, faeces, digesta, sand, or fibrous material can all contribute to impaction Predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility.
*Antihelminthic administration or large parasite burdens can also lead to impaction.

====== Extrinsic ======
Obstruction of the intestine due to external factors such as tumours, abscesses, and fibrous adhesions is a common occurrence.
*Neoplasia in structures adjacent to the intestines can spread and cause external compression. Pancreatic tumours in particular can extend and impinge on the duodenum.
*Inflammatory adhesions, following gut perforation, peritonitis or surgery, consist of fibrous tissue bands that may restrict intestinal motility and cause kinks in the mesentery.
*Pedicles of tumours such as lipomas in horses can become wound in loops of intestine leading to obstruction and possible strangulation.
*Prostatic enlargement in the dog can lead to compression of the rectum.

===== Functional =====
*Megacolon
*Paralytic ileus is a common condition that can occur following trauma or abdominal surgery. Intestinal stasis leads to distension with gas and fluid as well as a flaccid intestinal wall.

====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T18:56:17Z

Mayazoey: /* Mechanical */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction, pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses greater than 4 years of age. Typically, they lodge at the pelvic flexure or the transverse colon.

====== Impaction ======
Impaction of the colon can occur in all species.
*In the dog and cat, dehydrated faecal material is the main cause of impaction.
*In the horse, faeces, digesta, sand, or fibrous material can all contribute to impaction Predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility.
*Antihelminthic administration or large parasite burdens can also lead to impaction.

====== Extrinsic ======
Obstruction of the intestine due to external factors such as tumours, abscesses, and fibrous adhesions is a common occurrence.
*Neoplasia in structures adjacent to the intestines can spread and cause external compression. Pancreatic tumours in particular can extend and impinge on the duodenum.
*Inflammatory adhesions, following gut perforation, peritonitis or surgery, consist of fibrous tissue bands that may restrict intestinal motility and cause kinks in the mesentery.
*Pedicles of tumours such as lipomas in horses can become wound in loops of intestine leading to obstruction and possible strangulation.
*Prostatic enlargement in the dog can lead to compression of the rectum.

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T18:54:40Z

Mayazoey: /* Foreign Bodies */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction, pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses. Typically, they lodge at the pelvic flexure or the transverse colon and affect horses greater than 4 years of age.

====== Impaction ======
Impaction of the colon can occur in all species.
*In the dog and cat, dehydrated faecal material is the main cause of impaction.
*In the horse, faeces, digesta, sand, or fibrous material can all contribute to impaction Predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility.
*Antihelminthic administration or large parasite burdens can also lead to impaction.

====== Extrinsic ======
Obstruction of the intestine due to external factors such as tumours, abscesses, and fibrous adhesions is a common occurrence.
*Neoplasia in structures adjacent to the intestines can spread and cause external compression. Pancreatic tumours in particular can extend and impinge on the duodenum.
*Inflammatory adhesions, following gut perforation, peritonitis or surgery, consist of fibrous tissue bands that may restrict intestinal motility and cause kinks in the mesentery.
*Pedicles of tumours such as lipomas in horses can become wound in loops of intestine leading to obstruction and possible strangulation.
*Prostatic enlargement in the dog can lead to compression of the rectum.

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T18:52:22Z

Mayazoey: /* Extrinsic */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction and lead to pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses. Typically, they lodge at the pelvic flexure or the transverse colon and affect horses greater than 4 years of age.
====== Impaction ======
Impaction of the colon can occur in all species.
*In the dog and cat, dehydrated faecal material is the main cause of impaction.
*In the horse, faeces, digesta, sand, or fibrous material can all contribute to impaction Predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility.
*Antihelminthic administration or large parasite burdens can also lead to impaction.

====== Extrinsic ======
Obstruction of the intestine due to external factors such as tumours, abscesses, and fibrous adhesions is a common occurrence.
*Neoplasia in structures adjacent to the intestines can spread and cause external compression. Pancreatic tumours in particular can extend and impinge on the duodenum.
*Inflammatory adhesions, following gut perforation, peritonitis or surgery, consist of fibrous tissue bands that may restrict intestinal motility and cause kinks in the mesentery.
*Pedicles of tumours such as lipomas in horses can become wound in loops of intestine leading to obstruction and possible strangulation.
*Prostatic enlargement in the dog can lead to compression of the rectum.

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T18:51:31Z

Mayazoey: /* Extrinsic */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction and lead to pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses. Typically, they lodge at the pelvic flexure or the transverse colon and affect horses greater than 4 years of age.
====== Impaction ======
Impaction of the colon can occur in all species.
*In the dog and cat, dehydrated faecal material is the main cause of impaction.
*In the horse, faeces, digesta, sand, or fibrous material can all contribute to impaction Predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility.
*Antihelminthic administration or large parasite burdens can also lead to impaction.

====== Extrinsic ======
Obstruction of the intestine due to external factors such as tumours, abscesses, and fibrous adhesions is a common occurrence.
*Neoplasia in structures adjacent to the intestines can spread and cause external compression. Pancreatic tumours in particular can extend and impinge on the duodenum.
*Inflammatory adhesions, following gut perforation, peritonitis or surgery for example, consist of fibrous tissue bands that may restrict intestinal motility and cause kinks in the mesentery.
*Pedicles of tumours such as lipomas in horses can become wound in loops of intestine leading to obstruction and possible strangulation.
*Prostatic enlargement in the dog can lead to compression of the rectum.

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T18:50:31Z

Mayazoey: /* Extrinsic */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction and lead to pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses. Typically, they lodge at the pelvic flexure or the transverse colon and affect horses greater than 4 years of age.
====== Impaction ======
Impaction of the colon can occur in all species.
*In the dog and cat, dehydrated faecal material is the main cause of impaction.
*In the horse, faeces, digesta, sand, or fibrous material can all contribute to impaction Predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility.
*Antihelminthic administration or large parasite burdens can also lead to impaction.

====== Extrinsic ======
Obstruction of the intestine due to external factors such as tumours, abscesses, and fibrous adhesions following peritonitis, perforation or surgery is a common occurrence.
*Neoplasia in structures adjacent to the intestines can spread and cause external compression. Pancreatic tumours in particular can extend and impinge on the duodenum.
*Inflammatory adhesions following peritonitis or surgery for example consist of fibrous tissue bands that may restrict intestinal motility and cause kinks in the mesentery.
*Pedicles of tumours such as lipomas in horses can become wound in loops of intestine leading to obstruction and possible strangulation.
*Prostatic enlargement in the dog can lead to compression of the rectum.

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T17:38:24Z

Mayazoey: /* Impaction */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction and lead to pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses. Typically, they lodge at the pelvic flexure or the transverse colon and affect horses greater than 4 years of age.
====== Impaction ======
Impaction of the colon can occur in all species.
*In the dog and cat, dehydrated faecal material is the main cause of impaction.
*In the horse, faeces, digesta, sand, or fibrous material can all contribute to impaction Predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility.
*Antihelminthic administration or large parasite burdens can also lead to impaction.

====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T17:37:28Z

Mayazoey: /* Impaction */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction and lead to pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses. Typically, they lodge at the pelvic flexure or the transverse colon and affect horses greater than 4 years of age.
====== Impaction ======
*Impaction of the colon can occur in all species.
*In the dog and cat, dehydrated faecal material is the main cause of impaction.
*In the horse, faeces, digesta, sand, or fibrous material can all contribute. Predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility. *Antihelminthic administration or large parasite burdens can also lead to impaction.

====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T17:35:55Z

Mayazoey: /* Impaction */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction and lead to pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses. Typically, they lodge at the pelvic flexure or the transverse colon and affect horses greater than 4 years of age.
====== Impaction ======
Impaction of the colon can occur in all species. In the dog and cat, dehydrated faecal material is the main cause of impaction whereas in the horse, faeces, digesta, sand, or fibrous material can all contribute. In horses, predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility. Antihelminthic administration or large parasite burdens can also lead to impaction.

====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T17:22:06Z

Mayazoey: /* Impaction */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction and lead to pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses. Typically, they lodge at the pelvic flexure or the transverse colon and affect horses greater than 4 years of age.
====== Impaction ======
Impacted ingesta/faeces within the intestines can occur in all species though it is especially common in horses. Predisposing factors in horses include poor dentition, a high roughage diet, and general debility.
*Commonly occurs in the equine colon although impaction due to fibrous ingesta can occur in the ileum.
*Can occur following antihelminthic administration, especially in horses.

====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T17:20:12Z

Mayazoey: /* Impaction */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction and lead to pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses. Typically, they lodge at the pelvic flexure or the transverse colon and affect horses greater than 4 years of age.
====== Impaction ======
Impacted ingesta/faeces within the intestines can occur in all species though it is especially common in horses. Predisposing factors in horses include poor dentition, a high roughage diet, and general debility.
*Impaction in the horse commonly occurs in the colon although impaction due to fibrous ingesta can occur in the ileum.
*Impaction can occur following antihelminthic administration, especially in horses.

====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T17:17:21Z

Mayazoey: /* Physical */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Mechanical =====
Mechanical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction and lead to pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses. Typically, they lodge at the pelvic flexure or the transverse colon and affect horses greater than 4 years of age.
====== Impaction ======
Impacted ingesta/faeces within the intestines can occur in all species though it is especially common in horses. Predisposing factors in horses include poor dentition, a high roughage diet, and general debility.
*Impaction commonly occurs in the equine colon although impaction due to fibrous ingesta can occur in the ileum.
*Impaction can be common, especially in horses following antihelminthic administration.
====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T11:42:41Z

Mayazoey: /* Physical */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Physical =====
Physical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement. The following figure illustrates the pathogenesis occurring in intestinal obstruction [Figure].
====== Foreign Bodies ======
*Foreign bodies of all types can be found in the intestines. While some may pass through posing no problems, others can cause acute obstruction and lead to pressure necrosis and eventually perforation. Foreign bodies can also be chronic, remaining for long periods of time without causing disturbance.
**Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses. Typically, they lodge at the pelvic flexure or the transverse colon and affect horses greater than 4 years of age.

parasites, objects
====== Impaction ======
====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T11:14:48Z

Mayazoey:

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Physical =====
Physical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement.
====== Enteroliths [picture] ======
====== Foreign Bodies ======
====== Impaction ======
====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T11:14:20Z

Mayazoey:

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
Introduction
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Physical =====
Physical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement.
====== Enteroliths [picture] ======
====== Foreign Bodies ======
====== Impaction ======
====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T11:11:32Z

Mayazoey: /* Comparative */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only a samll amount of fermentation occurs in the large intestine of carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse which reies heavily on the end products of microbial digestion that occur in the large intestine. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. Ruminants are an exception as fermentation largely occurs in the stomach. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Physical =====
Physical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement.
====== Enteroliths [picture] ======
====== Foreign Bodies ======
====== Impaction ======
====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T10:53:24Z

Mayazoey: /* Comparative */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only minimal fermentation is necessary for carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Physical =====
Physical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement.
====== Enteroliths [picture] ======
====== Foreign Bodies ======
====== Impaction ======
====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T10:52:12Z

Mayazoey: /* Comparative */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified into categories such as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only minimal fermentation is necessary for carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species (Reece, 2005). [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Reece, WO: Functional Anatomy and Physiology of Domestic Animals, 3rd ed., pp. 312-368. Lippincott Williams & Wilkins, London, England, 2005.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Physical =====
Physical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement.
====== Enteroliths [picture] ======
====== Foreign Bodies ======
====== Impaction ======
====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T10:48:50Z

Mayazoey: /* Comparative */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
The natural diets of different animal species largely govern the structure and function of the gastrointestinal tract.
Broadly, animals can be classified into categories such as carnivores, herbivores or omnivores according to diet. Digestion and absorption of nutrients in carnivorous animals such as the dog and cat takes place largely in the small intestine. Because only minimal fermentation is necessary for carnivores, they have a minimally developed caecum in comparison to nonruminating herbivores such as the horse. The pig, an omnivorous animal has both a relatively long small intestine and an expanded portion of the colon that aids in fermentation of the fibrous material in the diet. The following figures illustrate the differences between the gastrointestinal tracts of the main domestic animal species. [Figures!!]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Physical =====
Physical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement.
====== Enteroliths [picture] ======
====== Foreign Bodies ======
====== Impaction ======
====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T09:56:43Z

Mayazoey: /* Basic Anatomy and Physiology */

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
=== Introduction ===
The intestines are a portion of the alimentary tract extending from the pylorus to the anus. In mammals, the intestines are divided into two main segments: the small intestine and the large intestine. The small intestine, consisting of the duodenum, jejunum and ileum, acts as the main site of absorption for digestive products in the gastrointestinal tract. The large intestine, consisting of the caecum and colon, functions to extract water, electrolytes and nutrients as well as to concentrate and propulse faecal material to the rectum for defaecation.
Functional differences between the small and large intestine are reflected in their anatomic and histologic organisation (Figure 1). The small intestinal mucosa in many species is highly folded and made up of numerous villi that greatly increase the absorptive surface area. Enterocytes, the main absorptive cells, are the most numerous and characteristic cells of the small intestinal epithelium. Others include goblet cells, paneth cells, neuroendocrine cells, stem cells, and intraepithelial lymphocytes. Another important feature of the small intestine is the presence of Peyer's patches within the lamina propria. They contribute to immune function and generation of immune responses within the mucosa.

In contrast to the small intestine, the large intestinal mucosa has no villi and consists of 2 main cell types: absorptive cells and mucus secreting goblet cells. A distinguishing histologic and anatomic characteristic is the thick muscularis mucosa layer that aids in propulsion of faeces to the rectum. Another important feature is the presence of commensal bacteria which plays different roles depending upon the type of animal (Dyce et. al, 2002; Young & Heath, 2000).

=== Defense Mechanisms ===
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes - nonspecifically target bacteria and viruses
*Bile - kills some bacteria and viruses

==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Epithelial cells have a very high turnover rate thus preventing pathogens with a longer life cycle from successfully colonising.
==== Commensal flora ====
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007).
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM provide humoural immunity and help prevent attachment of pathogens to the intestinal epithelium.
*Lysozyme from Paneth cells inhibits bacterial growth (McGavin & Zachary, 2007).
=== Comparative ===
carnivores, ruminants,horse, swine, rabbits [pictures]

'''References''' 

Dyce KM, Sack WO, Wensing, CJG: Textbook of Veterinary Anatomy, 3rd ed, p. 129. Saunders, London, England, 2002.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

Young B, Heath, JW: Wheater's Functional Histology: A Text and Colour Atlas, 4th ed, pp. 249-274. Churchill Livinstone, London, England, 2000.

== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Physical =====
Physical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement.
====== Enteroliths [picture] ======
====== Foreign Bodies ======
====== Impaction ======
====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===

User:Mayazoey

2007-08-10T09:55:50Z

Mayazoey:

<big><center>[[Alimentary - includes liver and pancreas|'''BACK TO ALIMENTARY''']]</center></big>

'''Intestine'''

== Basic Anatomy and Physiology ==
== Pathology ==
=== Developmental Anomalies ===
==== Segmental ====
Segmental anomalies of the intestines are common and range from incomplete occlusion (stenosis) to complete occlusion (atresia) of the lumen.
===== Atresia ani =====
*A common congenital defect of the lower gastrointestinal tract.
*Both the anus and rectum can be affected.
*Occurs in all species but is most often seen in calves and pigs.
===== Atresia coli =====
*Considered the most common segmental anomaly of the intestine in domestic animals.
*Can affect in particular the spiral colon of Holstein calves and the small colon of foals.
===== Atresia ilei =====
*It is less common to see atresia in the small intestine.
*Mostly seen in calves.
==== Persistent Meckel's diverticulum ====
*Meckel's diverticulum is a remnant of the omphalomesenteric duct of the yolk sac.
*Is usually an incidental finding though it can be associated with impaction and or intussusception.
==== Megacolon ====
*Occurs in cats, dogs, and pigs.
*May be due to a lack of myenteric plexuses that occurs when neuroblasts fail to migrate from the nerual crest to the colorectal myenteric plexuses.
*Congenital colonic agangliosis, a condition occurring in white foals, can lead to megacolon. It is thought to be an autosomal recessive condition.

'''References''' 

Brown CC, Baker DC, Barker IK: Alimentary System. In: Jubb, Kennedy and Palmer's Pathology of Domestic Animals, ed. Maxie MG, 5th ed., pp. 1-296. Elsevier, Philadelphia, PA, 2007.

McGavin DM & Zachary, JF: Pathologic Basis of Veterinary Disease, 4th ed, pp. 301-393. Elsevier, St. Louis, Missouri, 2007.

=== Physical Disturbances ===
==== Obstruction ====
Intestinal obstruction can be the sequel to either mechanical or functional causes. Mechanical obstruction occurs due to physical blockage of the intestinal lumen whereas functional obstruction results from a decrease or inhibition of intestinal motility due to loss of smooth muscle contraction. (Brown et. al, 2007).
===== Physical =====
Physical obstruction of the intestine, either acute or chronic, can occur in all species of animals. Acute obstruction usually involves the upper or middle small intestine whereas chronic obstruction typically occurs in the distal small intestine or large intestine. Causes of obstruction can be divided into three main categories: intraluminal, intramural, or extrinsic. Intraluminal causes include food impaction and foreign bodies, intramural causes include neoplasia and extrinsic causes include adhesions, neoplasia and prostate enlargement.
====== Enteroliths [picture] ======
====== Foreign Bodies ======
====== Impaction ======
====== Extrinsic ======
Neoplasia, Adhesions, Prostate enlargement

===== Functional =====
====== Megacolon ======
====== Dysautonomia ======
Grass sickness in horses, Feline

==== Displacement ====
===== Hernias =====
====== Internal ======
====== External ======
===== Volvulus and Torsion =====
====== Ruminants======
caecal dilatation and torsion
====== Equine ======
right and left dorsal displacement
colonic torsion and volvulus
===== Intussusception =====
===== Renosplenic entrapment =====

=== Vascular Disturbances ===
pathogenesis
==== Venous congestion ====
==== Arterial thromboembolism ====
=== Inflammation ===
pathogenesis
* enteritis
* typhlitis
* colitis
* proctitis
? about subheadings as many fit under specific pathogens
notes subcategorising by types of enteritis???
==== Diseases of the epithelium ====
===== Diseases of absorptive enterocytes =====
===== Diseases of undifferentiated crypt cells =====
==== Diseases of the lamina propria ====
==== Inflammatory bowel disease ====
description of
===== Lymphocytic/plasmacytic enteritis =====
===== Idiopathic mucosal colitis =====
===== Eosinophilic enteritis =====
===== Granulomatous enteritis =====
===== Colitis =====
====== Typhlocolitis ======
in dogs: pipe to species specific section
includes histiocytic unlcerative colitis
trichuris vulpis, pipe to parasites

=== Neoplastic and Proliferative Lesions ===
description
==== Intesinal adenoma ====
==== Intestinal adenocarcinoma ====
==== Lymphoma ====
==== Mast cell tumours ====
==== Intestinal stromal tumours ====

=== Diarrhoea ===
definition and pathogenesis
characteristics of l.i. diarrhoea

=== Miscellaneous ===
==== Caecal or large intestine rupture ====
==== Diverticula ====
==== Intestinal lipofuscinosis ====

== Diseases due to pathogens ==
Bacteria, Viral, Mycotic brief explanation then pipe to different page
=== Bacterial ===
brief explanation
==== ''Escherichia coli'' ====
description
===== Enterotoxogenic colibacillosis =====
===== Enteropatholgenic colibacillosis =====
===== Postweaning colibacillosis =====
===== Enteroinvasive colibacillosis =====
===== Septicaemic colibacillosis =====
==== ''Salmonellosis'' ====
description
[[Link to salmonellosis in specific species]]
===== Peracute ''Salmonella'' septicaemia =====
===== Acute enteric salmonellosis =====
===== Chronic enteric salmonellosis =====
==== Clostridial enteritis ====
description
===== ''Clostridium perfringens'' type A =====
===== ''Clostridium perfringens'' type B =====
===== ''Clostridium perfringens'' type C =====
===== ''Clostridium perfringens'' type D =====
===== Other Clostridial diseases =====
====== ''Clostridium difficile'' ======
====== ''Clostridium piliforme'' =====
==== ''Yersiniosis'' ====
==== ''Lawsonian intracellularis'' ====
==== ''Campylobacter'' spp. ====
==== Paratuberculosis (Johne's disease) ====

=== Viral ===
description
Bovine viral diarrhoea
Rinderpest
Peste des petits ruminants
Malignant catarrhal fever
Herpesvirus
Adenovirus
Coronavirus
Rotavirus
Parvovirus

=== Mycotic ===
description
Intestinal phycomycosis and aspergillosis
Candidiasis
Intestinal histoplasmosis

== Diseases in Animal Species ==
=== Avian ===
coccidiosis
=== Carnivores ===
==== Cats ====
Panleucopenia
Feline infectious peritonitis
Feline leukaemia
Feline immunodeficiency virus
==== Dogs ====
Parvovirus 2
Distemper
Salmonella
Rotavirus
Coronavirus
Ascarids
Hookworms
Giardiasis
Neoplasms
Salmon poisoning
Haemorrhagic enteritis
=== Horses ===
Rhodococcus equi
Equine monocytic ehrlichiosis
Equine granulomatous enteritis
Clostridial enteritis
Lawsonian associated
Potomac horse fever
Parasites
Antibiotic associated diarrhoea
=== Rabbits ===
=== Ruminants ===
Bovine viral diarrhoea
Rinderpest
Malignant catarrhal fever
Paratuberculosis
Chlamydiosis
Parasitism (list specifics to l.i.)
Copper deficiency
Salmonellosis
Yersiniosis
Coccidiosis
Escherichia coli
Poisoning
Winter dysentery
=== Swine ===
Rotavirus
Transmissible gastroenteritis
Escherichia coli
Salmonella
Lawsonian intracellularis
Swine dysentery
Porcine circovirus 2
Intestinal spirochaetosis
Ascaris suum
== Parasites ==
Cryptosporidiosis
Giaridasis
Ascariasis
Hookworm diseas
Trichuriasis
Strongyloidosis
Pinworms
Cestodes
Trematodes
== Clinical Pathology ==
=== Approach to diagnosis of large intestinal disease ===
=== Laboratory evaluation of large intestinal disease ===
==== Diarrhoea ====
==== Weight loss ====
=== Routine diagnostic procedures ===
=== Further tests ===