Diarrhea in young red deer associated with infection with Cryptosporidium.

In an outbreak of diarrhea among 82 artificially reared red deer calves, 56 developed the disease and 20 subsequently died. During the outbreak 80% of diarrheal and 50% of apparently healthy calves excreted cryptosporidial oocysts in feces. The coincidence of infection with Crytosporidium and clinical diarrhea suggested a causal relationship. Histologic examination of intestinal sections from a necropsied deer calf showed lesions consistent with field and experimental cryptosporidiosis in other species. The deer Cryptosporidium subclinically infected newborn mice; in indirect immunofluorescence tests, it could not be distinguished from a calf Cryptosporidium.