Swine 10 Flashcards
Porcine Proliferative enteropathy (PPE) is caused by what pathogen
- lawsonia intracellularis
Swine dysentery is caused by what pathogen
brachyspira hyodysenteriae
Pathogens associated with diarrhea in grower-finisher pigs
n Coronaviruses (TGE, PED, delta)
n Porcine circovirus
n Trichuris suis
n Lawsonia intracellularis (PPE)
n Brachyspira spp
n Salmonella spp
Porcine Proliferative Enteropathy (PPE):
Before a causative agent was identified, there was a confusing group of diseases classified by pathological lesions
> what are the diseases associated with the chronic manifestation ( in grower & finisher hogs):
- PIA – Porcine Intestinal Adenomatosis (proliferative enteropathy)
- NE - Necrotic Enteritis (coagulative necrosis of mucosa)
- RI - Regional Ileitis (granulomatous inflammation, hypertrophy of muscle layers
Porcine Proliferative Enteropathy (PPE):
Before a causative agent was identified, there was a confusing group of diseases classified by pathological lesions
> what are the diseases associated with the Acute manifestation (in finisher hogs & adults):
PHE – Proliferative Hemorrhagic Enteropathy (severe GIT haemorrhage)
what does porcine intestinal adenomatosis look like on PM?
Porcine intestinal adenomatosis with no necrosis, only mucosal proliferative changes is seen involving mainly the ileum, with a thick-walled intestine (top) and a corrugated, hyperplastic appearance on the serosal surface visible (bottom right).
what happens if a pig lives long enough with necrotic enteritis? (visible on PM)
In necrotic enteritis, if the pig lives long enough, the necrotic membrane will slough off.
when does regional ileitis occur? what does its pathology look like?
Regional ileitis (hose pipe gut) occurs when the necrotic mucous membrane has sloughed away resulting in smooth muscle hypertrophy of the tunica muscularis, a natural response in a pig that survives the necrotic enteritis stage. It can be difficult to find the organisms in remnants of hyperplastic crypts in such cases. Most pigs have died by this stage.
characteristics of lawsonia intracellularis? what does it cause pathologically?
-Obligate intracellular bacterium
-Gram negative, non-spore forming, curved shaped rod
-Causes intestinal crypt epithelial cell proliferation
in what part of the intestine does lawsonia intracellularis generally live?
end of small intestine (ileum), beginning of spiral colon
pathogenesis of proliferative enteritis
- Exposure to Lawsonia intracellularis begins in nursery (fecal- oral)
- Incubation period: ~ 2-3 wks
- Penetrates the dividing crypt cells
- Infected cells:
> Fail to mature and continue to divide
> Result is hyperplastic crypts ->
“adenomatosis”
> Intestinal mucosa becomes: Thickened, inflamed, necrotic > Proliferative & necrotic lesions
is proliferative enteritis common? where geographically?
Infection is very prevalent and of worldwide significance
where does lawsonia live outside of pigs?
lives on rodents, carried on flies, boots
when L intracellularis infects grow-finish pigs, what do we see?
chronic disease:
PIA, NE, RI
when L intracellularis infects finish and gestation pigs, what do we see?
acute disease, PHE
clinical signs of chronic Lawsonia intracellularis infection? when is onset? how and when is it shed, and when is it common seasonally?
Onset:
- 6–20 weeks of age
- Slow growth, lethargy, weight loss
> Thin, razor backs, poor-doers - Diarrhea
> Normal to greyish colour, homogenous in appearance
Subclinical disease common:
§ Poor feed intake to anorexia
§ Weight variation in the pen
§ Some loose stool
§ Economic loss is important
Fecal shedding:
§ in subclinical animals may begin as
early as 3 weeks of age
§ May shed for ~10 weeks post
recovery
§ Common when temperature fluctuates – spring and fall.
Rule-out for chronic form of Lawsonia intracellularis infection?
Porcine circovirus type 2
Lawsonia intracellularis Clinical Signs: Acute (PHE)? who does it affect?
- Older finisher hogs (80+kg)
- Gilts and boars – breeding herd (4-12 months old)
- Acute to peracute death
- Acute blood loss anemia (pale)
- Anorexia
- Dark tarry (melena) to bloody diarrhea
ACUTE
n Young adults
n Recently moved
n Black diarrhea
n Pale
n Sudden death