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Category:Enteritis, Fibrinous/Haemorrhagic (view source)
Revision as of 21:11, 1 June 2010
, 21:11, 1 June 2010Created page with '==Pathology== * The mucosa eroded to produce lesions of darkish-red submucosa covered in dry, crumbly fibrin. * Is usually caused by severe damage due to secondary bacterial inf…'
==Pathology==
* The mucosa eroded to produce lesions of darkish-red submucosa covered in dry, crumbly fibrin.
* Is usually caused by severe damage due to secondary bacterial infection following an earlier milder insult.
* Tends to be more severe in the lower [[Small Intestine - Anatomy & Physiology|small intestine]] and upper [[Large Intestine - Anatomy & Physiology|large intestine]].
** Many severe infections tend to get worse further down the gut.
*** Catarrhal change may be seen in the upper [[Small Intestine - Anatomy & Physiology|small intestine]] and fibrinous change in the lower [[Small Intestine - Anatomy & Physiology|small intestine]]s.
** In the lower aprt of the bowel, where the inflammation is more severe, disease is more anaerobic.
*** Lesions are caused by anaerobic organisms- convert mild diseases into more serious disease.
==Salmonellosis==
* There are many different serotypes of [[Salmonella|''Salmonella'']].
** All can produce disease BUT only a few commonly produce illness in UK.
** ''Salmonella'' poses a serious risk to man.
** Some serotypes tend to be more species specific, whereas others can affect a wide range of species. For example:
*** [[Salmonella|'''''Salmonella enteritidis''''']]
*** [[Salmonella|'''''Salmonella typhimurium''''']]
**** Widespread in most species.
*** [[Salmonella|''''' Salmonella dublin''''']]
**** Cattle
*** [[Salmonella|'''''Salmonella cholerae suis''''']]
**** Pigs
**** Usually speticaemic.
**** Not very common now.
*** [[Salmonella|'''''Salmonella montevideo''''']]
**** Produces outbreaks from contaminated imported meat and bone meal.
** Strains are often named after where they were first isolated.
** Typing is important for epidemiology.
** All strains can occur epizootically, enzootically and sporadically.
** All strains can also produce very similar changes.
* Salmonellosis is NOT very common in the dog and cat.
* However, the horse is often a carrier.
** Stress may precipitate the disease, meaning Salmonellosis is seen often in veterinary hospitals.
===Pathogenesis===
* Disease is often seen associated with stress.
* organisms penetrate enterocytes before crossing the mucosa and entering macrophages.
** After entering macrophages, organins may then either remain localised to the gut, or are carried round the body to cause disease.
* There are 2 main types of disease- '''septicaemic''' and '''enteric'''.
** Each outbreak causes only one type of disease.
** Type of disease is linked to serotype- some serotyopres produce septicaemia, whereas others remain localised in the gut.
====Septicaemic Salmonellosis====
* Septicaemic salmonellosis is very dramatic and produces death quite suddenly.
* [[Intestine Diarrhoea - Pathology|diarrhoea]] is often not seen before death.
* This form of the disease is unusual in the very young.
=====Pathogenesis=====
* The organism [[Colon - Anatomy & Physiology|colon]]ises bowel epithelium, where it affects the [[Peyer's Patches - Anatomy & Physiology|Peyers patches]].
** It then invades macrophages, which enable it to invade across the epithelium to the submucosa. It may then either
*** Remain localised to submucosa, or
*** Spread to the lymph nodes and enter the circulation to become septicaemic.
* Animals may die at this stage (30%), but this depends on such factors as the infecting dose and strain.
* Is similar to septicaemic[[Escherichia coli|'' E. Coli'']].
=====Clinical=====
* Is usually post-weaning (is unusual in the very young animal).
** 6 to 9 months in calves.
** 6 to 10 weeks in piglets.
* Animals suffer from pyrexia, and occasionally a little bit of [[Intestine Diarrhoea - Pathology|diarrhoea]].
* Skin is reddened diffusely
** Bruise-like dark purplish-red blotched may be seen.
=====Pathology=====
* Intestines
** May show mild catarrhal enteritis, becoming fibrinous lower down.
** The bowel is generally flaccid, reddened and filled with fluid.
** Ecchymotic and petechial haemorrhages on serosa and mucosa.
** Enlarged, haemorrhagic mesenteric lymph nodes.
* Excessive blood-tinged peritoneal fluid.
* Lungs are collapsed and frothy.
* Heart is often dilated with ecchymotic haemorrhages.
* Viscera have a "half-cooked appearance"
** Pale in colour.
** The [[Liver - Anatomy & Physiology|liver]] and kidneys are also flabby and may have subcapsular haemorrhages.
** The [[Liver - Anatomy & Physiology|liver]] may contain small white foci of necrosis known as '''paratyphoid granulomas'''.
=====Diagnosis=====
* By culture of blood and from mesenteric lymph nodes (which are oedematous and red).
====Enteric Salmonellosis====
* Enteric Salmonellosis shows differences in clinical presentation between species.
** '''Horse''' - acute fatal colitis.
** '''Cows''' - lingering febrile [[Intestine Diarrhoea - Pathology|diarrhoea]] with passage of pseudomembranes.
** '''Calves''' - acute [[Intestine Diarrhoea - Pathology|diarrhoea]] like colibacillosis.
** '''Dogs''' - acute bouts of [[Intestine Diarrhoea - Pathology|diarrhoea]].
** '''Cats''' - febrile enterocolitis.
** '''Pigs''' - septicemia or enterocolitis.
=====Clinical=====
* Affected animals produce acute [[Intestine Diarrhoea - Pathology|diarrhoea]], which causes many deaths.
** Watery and yellow.
** May be tinged with a little blood.
* Animals may die from dehydration.
* In some outbreaks, particularly in pigs, chronic low-grade [[Intestine Diarrhoea - Pathology|diarrhoea]] only is seen.
* Calves usually die in acute stage, but may also recover.
=====Pathology=====
* Enteritis is seen throughout the gut, but is worse further along the gut.
** Inflammation is catarrhal in the [[Duodenum - Anatomy & Physiology|duodenum]].
** By the ileocaecal junction enteritis is often fibrinous, sometimes with formation of diptheric membranes on the mucosal surface.
* The necrotic and fibrinous changes particularly affect the Peyers patches and the caecal and [[Colon - Anatomy & Physiology|colon]]ic lymphoid nodules.
** May lead to "button ulcers" in the terminal [[Ileum - Anatomy & Physiology|ileum]] and [[Colon - Anatomy & Physiology|colon]].
*** These ulcers rupture very rarely.
* Focal necrosis may also be seen.
** Particularly in the [[Liver - Anatomy & Physiology|liver]], but also in the [[Spleen - Anatomy & Physiology|spleen]].
** Histologically, foci show a central zone of necrosis, surrounded by macrophages and lymphocytes- [[Intestine Inflammatory - Pathology#Septicaemic Salmonellosis|paratyphoid granulomas]].
*** Although this indicates the animal has had a systemic incfection, paratyphoid granulomas may be present without showing signs of septicaemia.
*** Enteric cases of salmonella infection nearly always show some evidence of systemic spread.
* Septicaemic form may relocalise in the gut, resulting in enteric disease.
=====Sequelae=====
* Animals can remain carriers for months/years following recovery from the acute [[Intestine Diarrhoea - Pathology|diarrhoea]] phase.
** Bacteria is shed from the bile duct and mesenteric lymph nodes.
*** A source of infection for other animals and people.
*** Shed particularly in times of stress.
* '''Stricture of the [[Rectum - Anatomy & Physiology|rectum]]'''.
** A possible sequel to acute salmonellosis, especially in the piglet.
** Just a few centimetres in from the [[[[Anus - Anatomy & Physiology|anus]] - Anatomy & Physiology|[[Anus - Anatomy & Physiology|anus]]]].
** Gives rise to:
**# Difficulty in passing faeces.
**# Mega[[Colon - Anatomy & Physiology|colon]]
**# thin watery [[Intestine Diarrhoea - Pathology|diarrhoea]] in small 'pencils'.
**# blown up abdomen
** Animals eventually die from the stricture if they are not first destroyed.
==Swine Dysentery==
* Swine dysentery gives rise to fibrinous/ haemorrhagic enteritis.
* A quite common and important disease.
* The disease is caused by [[Brachyspira hyodysenteriae|''Brachyspira hyodysenteriae'']].
** Is not seen in gnotobiotic animals - other enteric pathogens such as [[Fusobacterium|''Fusobacterium'']] or [[Bacteroides|''Bacteroides'']] may therefore also be required in order to produce disease.
* The disease is NOT systemic.
** Localised to the [[Large Intestine - Anatomy & Physiology|large intestine]]- in particular, the spiral [[Colon - Anatomy & Physiology|colon]].
* Swine dysentery is spread by the faeco-oral route, and is carried by pigs and rodents.
===Clinical===
* Affects post weaning pigs at approximately 4 months of age.
* White scour becomes a liquid dirty red / brown scour with a foul smell.
** Contains poorly digested focal shreds of mucosa and fibrin strands.
*** '''Mucoid covered faeces'''.
* There are three outcomes to infection; the animal may:
** Die
** There is a morbidity up to 90% in the herd, with up to 50% mortality.
** Recover
** Become chronically infected.
* Symptoms are due to loss of absorption in [[Colon - Anatomy & Physiology|colon]].
** The [[Colon - Anatomy & Physiology|colon]] is normally a key site of absorption for water and electrolytes in the pig.
===Pathology===
* The serosa of the spiral [[Colon - Anatomy & Physiology|colon]] may appear shiny from the outside.
** Is turgid and oedematous.
** In severe cases, haemorrhage may be seen.
* The [[Small Intestine - Anatomy & Physiology|small intestine]] NOT affected.
* Fibrinous deposits are seen on the mucosa as the disease progresses.
** The mucosa underneath is eroded to expose blood vessels in lamina propria.
*** Accounts for the bleeding.
* Animals often recover, but have a low feed conversion ratio for sometime.
===Diagnosis===
* Silver stains show organisms in the epithelium of the mucosa.
* Also by immunofluorescence or electron microscopy.
==Parvovirus Enteritis==
* [[Parvoviridae|Parvovirus]] enteritis is also know as feline infectious enteritis or feline panleucopenia
* Since a vaccine is available, this disease is now uncommon.
* Over the last 10/15 years this has been seen primarily in the cat, but it is now also seen [[Intestine Inflammatory - Pathology#Canine Disease|in the dog]].
===Clinical===
* Manifests mainly in cats under 6 months old.
* Common in groups of unvaccinated cats.
** Produces big outbreaks, with [[Control of Feeding - Anatomy & Physiology#The Vomit Reflex|vomiting]] and pyrexia.
* Severe [[Control of Feeding - Anatomy & Physiology#The Vomit Reflex|vomiting]] and [[Intestine Diarrhoea - Pathology|diarrhoea]] occur.
** [[Intestine Diarrhoea - Pathology|diarrhoea]] is thin, watery and foul-smelling, and may also be blood-tinged.
*** Animals usually die despite treatment- die from dehydration.
* Animals suffer from fever.
* Pancytopaenia also occures.
** White blood cell count drops very low so as to become almost non-existent.
*** Drops to 1/ml from 10000/ml.
** Animals may therefore also die from other infections.
===Pathology===
====Gross====
* Virus targets crypt cells and lymphoid areas.
** Causes [[Intestine Inflammatory - Pathology#Villus Atrophy|villus atrophy]].
* In the cat, the intestine is thickened, turgid and swollen.
** Has a pale, dull and mottled appearance.
** The contents are rather dry - this gets worse lower down the gut.
* Areas of depression in the mucosa can be seen in the upper small bowel.
** Due to necrosis of tissue overlying Peyers patch.
* Lower down in the gut, enteritis is apparent.
** Cat- fibrinous.
** Dog- haemorrhagic.
*** Blood in lumen.
** Inflammation sometimes doesn't appear very severe.
* There may be very few lesions
** Histology is usually required for diagnosis.
* A '''radiomimetic virus'''.
** Affects all rapidly dividing cells and destroys them.
*** E.g. epithelium in the base of the crypts of [[Small Intestine - Anatomy & Physiology|small intestine]] are killed.
====Histological====
* The crypt lining cells undergo complete necrosis, but very little inflammation occurs.
** Collapse of villous architecture.
* May be fibrinous exudates on surface of mucosa.
* The submucosa and lamina propria are not affected and are left intact.
** Many [[Neutrophils - WikiBlood|neutrophils]] in the lamina propria.
* Cyst-like structures are seen in the deepest parts of the glands of the intestinal mucosa, if the animal survives for more than a few days.
** Flattened epithelial cells line these cystic glands.
*** Are enterocytes trying to repair the damage.
*** However, animals usually die from dehydration or secondary infection before the mucosa recovers.
* Inclusion bodies may be seen, but these are very hard to find.
* May get [[Lymphocytes - WikiBlood|lymphocyte]] invasion of mucosa.
* [[Lymph Nodes - Anatomy & Physiology|Lymph nodes]] appear pale and oedematous, and almost aplastic.
* [[Bone Marrow - Anatomy & Physiology|Bone marrow]] appears pale and fatty looking and is depleted of cells.
===Canine Disease===
* Until 1978 Parvovirus enteriris was totally unknown in dogs.
* First seen in dogs in Australia.
** Apeared very similar but perhaps slightly worse than the disease seen in the cat.
** A new and distinct disease, but the virus is very closely related to the feline virus.
*** Viral DNA is 98% homologous to the feline virus.
** The canine virus does NOT cause disease in cats.
* '''Clinical'''
** Causes enteritis in young dogs over 6 weeks old.
** Causes myocarditis in puppies.
** Mainly affects the [[Small Intestine - Anatomy & Physiology|small intestine]].
* Vaccines are very effective, but the virus is hardy and survives in the environment.
* Diagnosis:
** Look for viral antigen in the faeces by the red cell agglutination test.
** Immunoflurescence.
** ELISA.
** Serology.
==Bacterial septicaemia and enteritis==
* Some severe acute septicaemias cause very severe acute haemorrhagic enteritis with bleeding into the [[Alimentary - Anatomy & Physiology|alimentary tract]].
* Death is usually rapid.
* Fairly easy to diagnose
** [[Small Intestine - Anatomy & Physiology|small intestine]] is full of dark, tarry, partly clotted blood (like black currant jelly).
* Associated with severe systemic disease, e.g.
** '''Anthrax''' in cattle ([[Bacillus anthracis|''Bacillus anthracis'']]).
** '''Leptospirosis''' in dogs.
*** Especially [[Leptospira|''L. icterohaemorrhagiae'']].
* Do not confuse with [[Warfarin Poisoning|warfarin poisoning]].
** Also gives blood in [[Forestomach - Anatomy & Physiology|stomach]] and intestine BUT there are no signs of inflammatory disease.
===Lamb Dysentery (Enterotoxaemia with Blood)===
* [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']] causes very severe acute haemorrhagic enteritis.
** Usually affects young farm animals
*** May also be seen in pets.
* Type B [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']] infection of lambs leads to '''lamb dysentery'''.
====Clinical====
* Lamb dysentery is usually seen in lambs under 2 weeks of age.
** Related to being kept in a cold, dirty environment, with build-up of infection during the lambing season.
* Lambs may produce bloodstained [[Intestine Diarrhoea - Pathology|diarrhoea]] before death, but they often die before this effect is apparent.
* Diagnosed by culturing contents of gut.
====Pathology====
=====Gross=====
* The gut is blown and distended with foamy ,bloody contents.
* Sometimes ulceration with perforation and fibrinousperitonitis is seen.
* Focal or diffuse congestion and haemorrhages.
=====Histological=====
*Coagulative necrosis of villi.
* Oedema.
* Haemorrhage.
* Influx of inflammatory cells in the lamina propria and submucosa.
====Similar Conditions====
* '''Piglets''' show similar disease caused by [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']] type C (and sometimes type B)
** May look similar to a volvulus but with no twist present.
* In '''adult sheep''' [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']] type B infection causes '''Struck'''.
** Enterotoxigenic gastritis.
** Acute sudden death with haemorrhagic enteritis
** Haemorrhagic enteritis is not as severe as in lambs, and tends to be more patchy.
===Colitis X===
* Affects the horse.
* Sudden onset with haemorrhages throughout body (shock) and sometimes acute foul smelling diarhoea.
* [[Colon - Anatomy & Physiology|colon]] is acutely haemorhagic and oedematous with mucosal necrosis.
* Associated with [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']].
* Possibly an enterotoxaemia.
[[Category:Intestine_-_Inflammatory_Pathology_by_Type]]
* The mucosa eroded to produce lesions of darkish-red submucosa covered in dry, crumbly fibrin.
* Is usually caused by severe damage due to secondary bacterial infection following an earlier milder insult.
* Tends to be more severe in the lower [[Small Intestine - Anatomy & Physiology|small intestine]] and upper [[Large Intestine - Anatomy & Physiology|large intestine]].
** Many severe infections tend to get worse further down the gut.
*** Catarrhal change may be seen in the upper [[Small Intestine - Anatomy & Physiology|small intestine]] and fibrinous change in the lower [[Small Intestine - Anatomy & Physiology|small intestine]]s.
** In the lower aprt of the bowel, where the inflammation is more severe, disease is more anaerobic.
*** Lesions are caused by anaerobic organisms- convert mild diseases into more serious disease.
==Salmonellosis==
* There are many different serotypes of [[Salmonella|''Salmonella'']].
** All can produce disease BUT only a few commonly produce illness in UK.
** ''Salmonella'' poses a serious risk to man.
** Some serotypes tend to be more species specific, whereas others can affect a wide range of species. For example:
*** [[Salmonella|'''''Salmonella enteritidis''''']]
*** [[Salmonella|'''''Salmonella typhimurium''''']]
**** Widespread in most species.
*** [[Salmonella|''''' Salmonella dublin''''']]
**** Cattle
*** [[Salmonella|'''''Salmonella cholerae suis''''']]
**** Pigs
**** Usually speticaemic.
**** Not very common now.
*** [[Salmonella|'''''Salmonella montevideo''''']]
**** Produces outbreaks from contaminated imported meat and bone meal.
** Strains are often named after where they were first isolated.
** Typing is important for epidemiology.
** All strains can occur epizootically, enzootically and sporadically.
** All strains can also produce very similar changes.
* Salmonellosis is NOT very common in the dog and cat.
* However, the horse is often a carrier.
** Stress may precipitate the disease, meaning Salmonellosis is seen often in veterinary hospitals.
===Pathogenesis===
* Disease is often seen associated with stress.
* organisms penetrate enterocytes before crossing the mucosa and entering macrophages.
** After entering macrophages, organins may then either remain localised to the gut, or are carried round the body to cause disease.
* There are 2 main types of disease- '''septicaemic''' and '''enteric'''.
** Each outbreak causes only one type of disease.
** Type of disease is linked to serotype- some serotyopres produce septicaemia, whereas others remain localised in the gut.
====Septicaemic Salmonellosis====
* Septicaemic salmonellosis is very dramatic and produces death quite suddenly.
* [[Intestine Diarrhoea - Pathology|diarrhoea]] is often not seen before death.
* This form of the disease is unusual in the very young.
=====Pathogenesis=====
* The organism [[Colon - Anatomy & Physiology|colon]]ises bowel epithelium, where it affects the [[Peyer's Patches - Anatomy & Physiology|Peyers patches]].
** It then invades macrophages, which enable it to invade across the epithelium to the submucosa. It may then either
*** Remain localised to submucosa, or
*** Spread to the lymph nodes and enter the circulation to become septicaemic.
* Animals may die at this stage (30%), but this depends on such factors as the infecting dose and strain.
* Is similar to septicaemic[[Escherichia coli|'' E. Coli'']].
=====Clinical=====
* Is usually post-weaning (is unusual in the very young animal).
** 6 to 9 months in calves.
** 6 to 10 weeks in piglets.
* Animals suffer from pyrexia, and occasionally a little bit of [[Intestine Diarrhoea - Pathology|diarrhoea]].
* Skin is reddened diffusely
** Bruise-like dark purplish-red blotched may be seen.
=====Pathology=====
* Intestines
** May show mild catarrhal enteritis, becoming fibrinous lower down.
** The bowel is generally flaccid, reddened and filled with fluid.
** Ecchymotic and petechial haemorrhages on serosa and mucosa.
** Enlarged, haemorrhagic mesenteric lymph nodes.
* Excessive blood-tinged peritoneal fluid.
* Lungs are collapsed and frothy.
* Heart is often dilated with ecchymotic haemorrhages.
* Viscera have a "half-cooked appearance"
** Pale in colour.
** The [[Liver - Anatomy & Physiology|liver]] and kidneys are also flabby and may have subcapsular haemorrhages.
** The [[Liver - Anatomy & Physiology|liver]] may contain small white foci of necrosis known as '''paratyphoid granulomas'''.
=====Diagnosis=====
* By culture of blood and from mesenteric lymph nodes (which are oedematous and red).
====Enteric Salmonellosis====
* Enteric Salmonellosis shows differences in clinical presentation between species.
** '''Horse''' - acute fatal colitis.
** '''Cows''' - lingering febrile [[Intestine Diarrhoea - Pathology|diarrhoea]] with passage of pseudomembranes.
** '''Calves''' - acute [[Intestine Diarrhoea - Pathology|diarrhoea]] like colibacillosis.
** '''Dogs''' - acute bouts of [[Intestine Diarrhoea - Pathology|diarrhoea]].
** '''Cats''' - febrile enterocolitis.
** '''Pigs''' - septicemia or enterocolitis.
=====Clinical=====
* Affected animals produce acute [[Intestine Diarrhoea - Pathology|diarrhoea]], which causes many deaths.
** Watery and yellow.
** May be tinged with a little blood.
* Animals may die from dehydration.
* In some outbreaks, particularly in pigs, chronic low-grade [[Intestine Diarrhoea - Pathology|diarrhoea]] only is seen.
* Calves usually die in acute stage, but may also recover.
=====Pathology=====
* Enteritis is seen throughout the gut, but is worse further along the gut.
** Inflammation is catarrhal in the [[Duodenum - Anatomy & Physiology|duodenum]].
** By the ileocaecal junction enteritis is often fibrinous, sometimes with formation of diptheric membranes on the mucosal surface.
* The necrotic and fibrinous changes particularly affect the Peyers patches and the caecal and [[Colon - Anatomy & Physiology|colon]]ic lymphoid nodules.
** May lead to "button ulcers" in the terminal [[Ileum - Anatomy & Physiology|ileum]] and [[Colon - Anatomy & Physiology|colon]].
*** These ulcers rupture very rarely.
* Focal necrosis may also be seen.
** Particularly in the [[Liver - Anatomy & Physiology|liver]], but also in the [[Spleen - Anatomy & Physiology|spleen]].
** Histologically, foci show a central zone of necrosis, surrounded by macrophages and lymphocytes- [[Intestine Inflammatory - Pathology#Septicaemic Salmonellosis|paratyphoid granulomas]].
*** Although this indicates the animal has had a systemic incfection, paratyphoid granulomas may be present without showing signs of septicaemia.
*** Enteric cases of salmonella infection nearly always show some evidence of systemic spread.
* Septicaemic form may relocalise in the gut, resulting in enteric disease.
=====Sequelae=====
* Animals can remain carriers for months/years following recovery from the acute [[Intestine Diarrhoea - Pathology|diarrhoea]] phase.
** Bacteria is shed from the bile duct and mesenteric lymph nodes.
*** A source of infection for other animals and people.
*** Shed particularly in times of stress.
* '''Stricture of the [[Rectum - Anatomy & Physiology|rectum]]'''.
** A possible sequel to acute salmonellosis, especially in the piglet.
** Just a few centimetres in from the [[[[Anus - Anatomy & Physiology|anus]] - Anatomy & Physiology|[[Anus - Anatomy & Physiology|anus]]]].
** Gives rise to:
**# Difficulty in passing faeces.
**# Mega[[Colon - Anatomy & Physiology|colon]]
**# thin watery [[Intestine Diarrhoea - Pathology|diarrhoea]] in small 'pencils'.
**# blown up abdomen
** Animals eventually die from the stricture if they are not first destroyed.
==Swine Dysentery==
* Swine dysentery gives rise to fibrinous/ haemorrhagic enteritis.
* A quite common and important disease.
* The disease is caused by [[Brachyspira hyodysenteriae|''Brachyspira hyodysenteriae'']].
** Is not seen in gnotobiotic animals - other enteric pathogens such as [[Fusobacterium|''Fusobacterium'']] or [[Bacteroides|''Bacteroides'']] may therefore also be required in order to produce disease.
* The disease is NOT systemic.
** Localised to the [[Large Intestine - Anatomy & Physiology|large intestine]]- in particular, the spiral [[Colon - Anatomy & Physiology|colon]].
* Swine dysentery is spread by the faeco-oral route, and is carried by pigs and rodents.
===Clinical===
* Affects post weaning pigs at approximately 4 months of age.
* White scour becomes a liquid dirty red / brown scour with a foul smell.
** Contains poorly digested focal shreds of mucosa and fibrin strands.
*** '''Mucoid covered faeces'''.
* There are three outcomes to infection; the animal may:
** Die
** There is a morbidity up to 90% in the herd, with up to 50% mortality.
** Recover
** Become chronically infected.
* Symptoms are due to loss of absorption in [[Colon - Anatomy & Physiology|colon]].
** The [[Colon - Anatomy & Physiology|colon]] is normally a key site of absorption for water and electrolytes in the pig.
===Pathology===
* The serosa of the spiral [[Colon - Anatomy & Physiology|colon]] may appear shiny from the outside.
** Is turgid and oedematous.
** In severe cases, haemorrhage may be seen.
* The [[Small Intestine - Anatomy & Physiology|small intestine]] NOT affected.
* Fibrinous deposits are seen on the mucosa as the disease progresses.
** The mucosa underneath is eroded to expose blood vessels in lamina propria.
*** Accounts for the bleeding.
* Animals often recover, but have a low feed conversion ratio for sometime.
===Diagnosis===
* Silver stains show organisms in the epithelium of the mucosa.
* Also by immunofluorescence or electron microscopy.
==Parvovirus Enteritis==
* [[Parvoviridae|Parvovirus]] enteritis is also know as feline infectious enteritis or feline panleucopenia
* Since a vaccine is available, this disease is now uncommon.
* Over the last 10/15 years this has been seen primarily in the cat, but it is now also seen [[Intestine Inflammatory - Pathology#Canine Disease|in the dog]].
===Clinical===
* Manifests mainly in cats under 6 months old.
* Common in groups of unvaccinated cats.
** Produces big outbreaks, with [[Control of Feeding - Anatomy & Physiology#The Vomit Reflex|vomiting]] and pyrexia.
* Severe [[Control of Feeding - Anatomy & Physiology#The Vomit Reflex|vomiting]] and [[Intestine Diarrhoea - Pathology|diarrhoea]] occur.
** [[Intestine Diarrhoea - Pathology|diarrhoea]] is thin, watery and foul-smelling, and may also be blood-tinged.
*** Animals usually die despite treatment- die from dehydration.
* Animals suffer from fever.
* Pancytopaenia also occures.
** White blood cell count drops very low so as to become almost non-existent.
*** Drops to 1/ml from 10000/ml.
** Animals may therefore also die from other infections.
===Pathology===
====Gross====
* Virus targets crypt cells and lymphoid areas.
** Causes [[Intestine Inflammatory - Pathology#Villus Atrophy|villus atrophy]].
* In the cat, the intestine is thickened, turgid and swollen.
** Has a pale, dull and mottled appearance.
** The contents are rather dry - this gets worse lower down the gut.
* Areas of depression in the mucosa can be seen in the upper small bowel.
** Due to necrosis of tissue overlying Peyers patch.
* Lower down in the gut, enteritis is apparent.
** Cat- fibrinous.
** Dog- haemorrhagic.
*** Blood in lumen.
** Inflammation sometimes doesn't appear very severe.
* There may be very few lesions
** Histology is usually required for diagnosis.
* A '''radiomimetic virus'''.
** Affects all rapidly dividing cells and destroys them.
*** E.g. epithelium in the base of the crypts of [[Small Intestine - Anatomy & Physiology|small intestine]] are killed.
====Histological====
* The crypt lining cells undergo complete necrosis, but very little inflammation occurs.
** Collapse of villous architecture.
* May be fibrinous exudates on surface of mucosa.
* The submucosa and lamina propria are not affected and are left intact.
** Many [[Neutrophils - WikiBlood|neutrophils]] in the lamina propria.
* Cyst-like structures are seen in the deepest parts of the glands of the intestinal mucosa, if the animal survives for more than a few days.
** Flattened epithelial cells line these cystic glands.
*** Are enterocytes trying to repair the damage.
*** However, animals usually die from dehydration or secondary infection before the mucosa recovers.
* Inclusion bodies may be seen, but these are very hard to find.
* May get [[Lymphocytes - WikiBlood|lymphocyte]] invasion of mucosa.
* [[Lymph Nodes - Anatomy & Physiology|Lymph nodes]] appear pale and oedematous, and almost aplastic.
* [[Bone Marrow - Anatomy & Physiology|Bone marrow]] appears pale and fatty looking and is depleted of cells.
===Canine Disease===
* Until 1978 Parvovirus enteriris was totally unknown in dogs.
* First seen in dogs in Australia.
** Apeared very similar but perhaps slightly worse than the disease seen in the cat.
** A new and distinct disease, but the virus is very closely related to the feline virus.
*** Viral DNA is 98% homologous to the feline virus.
** The canine virus does NOT cause disease in cats.
* '''Clinical'''
** Causes enteritis in young dogs over 6 weeks old.
** Causes myocarditis in puppies.
** Mainly affects the [[Small Intestine - Anatomy & Physiology|small intestine]].
* Vaccines are very effective, but the virus is hardy and survives in the environment.
* Diagnosis:
** Look for viral antigen in the faeces by the red cell agglutination test.
** Immunoflurescence.
** ELISA.
** Serology.
==Bacterial septicaemia and enteritis==
* Some severe acute septicaemias cause very severe acute haemorrhagic enteritis with bleeding into the [[Alimentary - Anatomy & Physiology|alimentary tract]].
* Death is usually rapid.
* Fairly easy to diagnose
** [[Small Intestine - Anatomy & Physiology|small intestine]] is full of dark, tarry, partly clotted blood (like black currant jelly).
* Associated with severe systemic disease, e.g.
** '''Anthrax''' in cattle ([[Bacillus anthracis|''Bacillus anthracis'']]).
** '''Leptospirosis''' in dogs.
*** Especially [[Leptospira|''L. icterohaemorrhagiae'']].
* Do not confuse with [[Warfarin Poisoning|warfarin poisoning]].
** Also gives blood in [[Forestomach - Anatomy & Physiology|stomach]] and intestine BUT there are no signs of inflammatory disease.
===Lamb Dysentery (Enterotoxaemia with Blood)===
* [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']] causes very severe acute haemorrhagic enteritis.
** Usually affects young farm animals
*** May also be seen in pets.
* Type B [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']] infection of lambs leads to '''lamb dysentery'''.
====Clinical====
* Lamb dysentery is usually seen in lambs under 2 weeks of age.
** Related to being kept in a cold, dirty environment, with build-up of infection during the lambing season.
* Lambs may produce bloodstained [[Intestine Diarrhoea - Pathology|diarrhoea]] before death, but they often die before this effect is apparent.
* Diagnosed by culturing contents of gut.
====Pathology====
=====Gross=====
* The gut is blown and distended with foamy ,bloody contents.
* Sometimes ulceration with perforation and fibrinousperitonitis is seen.
* Focal or diffuse congestion and haemorrhages.
=====Histological=====
*Coagulative necrosis of villi.
* Oedema.
* Haemorrhage.
* Influx of inflammatory cells in the lamina propria and submucosa.
====Similar Conditions====
* '''Piglets''' show similar disease caused by [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']] type C (and sometimes type B)
** May look similar to a volvulus but with no twist present.
* In '''adult sheep''' [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']] type B infection causes '''Struck'''.
** Enterotoxigenic gastritis.
** Acute sudden death with haemorrhagic enteritis
** Haemorrhagic enteritis is not as severe as in lambs, and tends to be more patchy.
===Colitis X===
* Affects the horse.
* Sudden onset with haemorrhages throughout body (shock) and sometimes acute foul smelling diarhoea.
* [[Colon - Anatomy & Physiology|colon]] is acutely haemorhagic and oedematous with mucosal necrosis.
* Associated with [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']].
* Possibly an enterotoxaemia.
[[Category:Intestine_-_Inflammatory_Pathology_by_Type]]