Syn: Porcine intestinal adenomatosis (PIA), proliferative haemorrhagic enteropathy (PHE), ileitis, regional ileitis (RI), necrotic enteritis

Diagnosis

Clinical signs, necropsy findings, histopathological examination of affected intestine, and bacteriological examination.

Lawsonia intracellularis is the aetiological agent. It is an intracellular organism and requires rat enterocyte cell lines for maintenance. The uncomplicated proliferation of mucosa due to L. intracellularis is referred to as PIA, while additional changes that may be superimposed on this lesion may result in regional ileitis (muscular hypertrophy), necrotic enteritis (coagulative necrosis) or PHE (haemorrhage). It is likely that necrotic enteritis represents secondary bacterial infection superimposed on a primary L.intracellularis lesion.

PIA and RI are associated with weaner ill thrift, but PIA can occur in all ages. PHE is associated with sudden death in finisher and breeder pigs, while necrotic enteritis can cause mortalities in grower pigs.

Specimens required

1. Sections of affected intestine (especially ileum and colon), submitted chilled for bacteriology for differential diagnosis.
2. Sections of affected intestine, submitted in buffered formalin for histopathology.
3. Impression smears of affected intestinal mucosa for bacteriology (MZN stain).
4. Fresh intestinal contents or faeces for PCR.

NB.
PCR tests are available for three enteric pathogens: Brachyspira hyodysenteriae, Brachyspira pilisicoli and Lawsonia intracellularis.