This paper describes the epidemiology, clinical signs and pathology of an outbreak of cryptosporidiosis in calves in Southern Brazil. Thirty-five out of 400 calves with 30-45 days of age were affected and 16 died. The calves were born weak and just after birth they had yellow diarrhea, weight loss, dehydration, depression, and death between 10 and 15 days after onset of clinical signs. Congestion of the bowel and mesenteric blood vessels were observed at necropsy. Intestinal distension by gas and dilation of lymphatic vessels were also observed. Microscopically, the intestine showed flattening of the villi with necrosis and atrophy. Adhered to the surface of the villus epithelial cells there were round basophilic structures of 2- to 5-μm-diameter compatible with Cryptosporidium spp. Electron microscopy revealed the presence of different stages of the agent adhered to the microvilli of enterocytes. We alert the importance of cryptosporidiosis as a primary agent of diarrhea in calves. Preventive measures to reduce economic losses, environmental contamination, and also decrease of risk for public health are necessary.
Cryptosporidiosis; Cryptosporidium spp.; calves; diarrhea
