[Cryptosporidium: a "new" factor in the aetiology of neonatal diarrhoea in calves].

In recent years, Cryptosporidium, a coccidian parasite of the intestine, has been associated with neonatal diarrhoea in calves. Current knowledge of the organism with regard to classification, host-specificity, life cycle, pathology, incidence, clinical treatment, prevention and diagnosis is reviewed in the present paper. In addition, Cryptosporidium infection in calves in the Netherlands is reported for the first time. The typical 4 micrometer oocysts were observed on microscopic examination of te faeces of a three-week-old calf with severe diarrhoea and in the faeces of three other clinical normal calves of the same group. Tests performed simultaneously for the presence of rotaviruses, bovine coronaviruses or K99-positive E. coli were negative. Histological and electron-microscopic studies of the intestines of orally inoculated baby mice served to verify the diagnosis of cryptosporidiosis.