Diarrhea associated with intestinal Cryptosporidiosis in turkeys.

Turkey poults were suffering from diarrhea on a farm in which several previous grow-outs of turkeys had experienced a clinically identical problem. Upon necropsy, significant gross lesions were restricted to the gastrointestinal tract. Segments of small intestine were pale and distended with cloudy mucoid material and a few gas bubbles. The ceca contained fluid and gas. Fresh organ portions were collected and fixed in 10% neutral buffered formalin and submitted for histological processing and examination (light microscopy and scanning and transmission electron microscopy). Small (2-4 micron) basophilic bodies identified as Cryptosporidium sp. were present in enterocytes of the middle and lower small intestine. The villi were moderately atrophic, the crypts were hypertrophic, and the lamina propria was infiltrated by large numbers of lymphocytes, heterophils, and fewer macrophages and plasma cells. Numerous intraepithelial leukocytes and exocytosing inflammatory cells also were present.