Infection of a calf with the enteric coronavirus strain Paris.

A tissue-culture-grown enteric coronavirus infected the whole of the gastrointestinal tract and caused enteritis and diarrhoea in a 10-day-old gnotobiotic Friesian calf. Diarrhoea occurred 2 days after inoculation and excretion of virus in faeces and rectal swabs increased until necropsy at 3 days. Virus growth, as detected by indirect immunofluorescence, virus isolation, and thin section electron microscopy, was most extensive in the epithelium of the colon and rectum at 3 days after inoculation. No virus was detected in other organs or in the pleural, peritoneal and oropharyngeal cavities. The origin and host specificity of this coronavirus is discussed.