Difference between revisions of "Porcine Adenomatosis Complex"

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* Characteristic proliferation of mucosa.
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#redirect[[Lawsonia intracellularis]]
* Known as PIA - porcine intestinal adenomatosis.
 
 
 
====Clinical====
 
 
 
* Really only seen in the pig.
 
** Can affect all ages of pig.
 
* Clinical signs are variable.
 
** Anything from poor weight gain to diarrhoea, weight loss, cachexia and death.
 
* Seen often as problem in closed, low infection herds. 
 
** Not seen in pigs with lots of other pathogens in guts.
 
 
 
====Pathogenesis====
 
 
 
* Caused by [[Lawsonia intracellularis|''Lawsonia intracellularis'']].
 
** A spirochete that does not grow well except in tissue culture.
 
 
 
====Pathology====
 
 
 
* The terminal [[Small Intestine Overview - Anatomy & Physiology|small intestine]] and [[Colon - Anatomy & Physiology|colon]] are affected by proliferation of the mucosal epithelium.
 
* '''Gross'''
 
** Thickened mucosal epithelium.
 
** Has almost polypoid-like nodules several millimetres in diameter.
 
** Undifferentiated epithelium replaces goblet cells.
 
*** Appears almost neoplastic.
 
* '''Histologically'''
 
** Very similar to a virus induced proliferation.
 
** Organisms seen in the apical part of epithelial cells lining glands of terminal [[Ileum - Anatomy & Physiology|ileum]], [[Colon - Anatomy & Physiology|colon]] and [[Caecum - Anatomy & Physiology|caecum]].
 
** May produce mild ulceration in mucosa and mild inflammatory infiltration.
 
 
 
 
 
* Porcine adenomatosis complex can be divided into four distinct syndromes:
 
*# '''Intestinal adenomatosis'''
 
*#* THe basic hyperplastic and metaplastic changes are seen in the epithelium. [[Image:porcine intestinal adenomatosis campylobacter.jpg|thumb|right|150px|Campylobacter mucosalis in intracellular porcine intestinal adenomatosis (Courtesy of Bristol BioMed Image Archive)]]
 
*#* Causes chronic weight loss and diarrhoea.
 
*# '''Necrotic enteritis'''
 
*#* Predominately affects the [[Colon - Anatomy & Physiology|colon]] and terminal [[Ileum - Anatomy & Physiology|ileum]].
 
*#* Parts of the hyperplastic mucosa develop erosions and ulcerations.
 
*#** These areas become [[Colon - Anatomy & Physiology|colon]]ised by ''Fusiformis'' baceria.
 
*#*** Gives areas of coagulative necrosis covered by a thick diptheretic membrane.
 
*# '''Terminal ileitis'''
 
*#* Characterised by marked hypertrophic thickening of the muscular portion of the wall of the terminal [[Ileum - Anatomy & Physiology|ileum]].
 
*#* Gives an attendant stenosis of the lumen of the [[Ileum - Anatomy & Physiology|ileum]].
 
*#* There is associated thickening of the mucosa due to hypertrophy and secondary granulomatous inflammation.
 
*#** This is presumably caused by a degree of obstruction to the passage of ingesta along the bowel caused by the mucosal hypertrophy.
 
*#* Appears very similar to Johnes disease
 
*#** Lots of mononuclear cells and a chronic granulomatous type of inflammation.
 
*# '''Proliferative haemorrhagic syndrome'''.
 
*#* The bowel shows proliferation but with ulceration and copious haemorrhage into the bowel lumen.
 
*#* Animals are often be found dead.
 
*#* The pathogenesis is unclear.
 
*#** May involve a type of hypersensitivity reaction or secondary infection of some type.
 
 
 
====Sequelae====
 
 
 
* Resolution.
 
* Necrotic enteritis.
 
* Secondary chronic infection (regional enteritis).
 
* Porcine haemorrhgaic enteritis (PHE).
 
 
 
 
 
[[Category:Enteritis,_Proliferative]][[Category:Intestinal Diseases - Pig]][[Category:Enteritis,_Bacterial]]
 
[[Category:To_Do_-_Kate]]
 

Latest revision as of 15:12, 14 March 2011