Reproduction of proliferative enteropathy in foals using porcine intestinal mucosal homogenate

Proliferative enteropathy (PE) is an intestinal disease that affects equine and several other species. The goal of this study is to determine whether proliferative enteropathy could be experimentally reproduced in foals. Seven foals were divided into two groups: A (n=5), and B (n=2). The foals were inoculated intragastrically with porcine intestinal mucosal homogenate (group A), or a placebo challenge (group B). Ante mortem and post mortem tests were performed. All foals were euthanised on day 22 post challenge. Physical examination detected variable signs of depression, colic, decreased appetite, diarrhoea, dehydration and emaciation in three foals in group A. At necropsy, one foal (foal 5, group A) was severely emaciated, the wall of the ileum and distal jejunum was thickened and the mucosa was corrugated and hyperaemic. Histologically, hyperplasia of immature enterocytes and reduced number of Paneth and goblet cells were observed. PCR confirmed the presence of Lawsonia intracellularis. The foals in groups A were positive for L. intracellularis by immunohistochemistry. The control foals (group B) remained physically normal, had no pathologic lesions and were negative by immunohistochemistry. PE was reproduced in foals using intestinal mucosal homogenate. Physical, gross and histopathologic alterations typical of PE were detected in some foals. The presence of L. intracellularis was confirmed by immunohistochemistry and/or PCR. The role of L. intracellularis from different species in the etiopathogenesis of PE in the horse was established.