Proliferative enteropathy

Proliferative enteropathy (PE) also known as proliferative ileitis, caused by the obligate intracellular bacterium Lawsonia intracellularis is a world widespread disease. It has been reported in a variety of species including pigs, horses, rabbits, hamsters...

The disease has two clinical manifestations on pigs: an acute haemorrhagic form often called porcine hemorrhagic enteropathy (PHE) and a more chronic proliferative form often referred as porcine intestinal adenomastosis (PIA).

Cases of acute hemorrhagic enteropathy occur most commonly in young adults 6 to 20 months old, but older animals can also be affected.

Since PE attacks the lower small intestine (ileum) it impairs digestion and can lead to clinical signs. Loose stools or watery diarrhoea may result along with loss of appetite, weight loss, reduce feed efficiency and anaemia (Euzeby, 1995).

Histologically, the affected tissues show marked proliferation of epithelial cells of the intestinal crypts. The magnitude of the proliferation varies widely but in developed lesions the wall is visibly thickened and the overall diameter increased.

Lawsonia intracellularis is a gram-negative intracellular bacterium, which preferentially grows within intestinal epithelial cells. It has not been yet cultivated in cell-free media (Lawson et al, 1995).

Gross necropsy and laboratory examinations are frequently applied to diagnose PE.