Isospora suis enteritis in piglets.

A species of porcine coccidia, Isospora suis, when inoculated into piglets, produced diarrhea, dehydration, weight loss and death. Gross lesions were characterized by a fibrino-necrotic membrane within the jejunum and ileum. Villous atrophy and variable erosion, often with an adhered necrotic membrane, were seen microscopically. Asexual and sexual stages of I. suis were seen within the intestinal epithelium and oocysts were recovered from the feces. The severity of clinical disease and lesions were dose-related.