Borna disease in naturally infected cattle.

Based on the immunohistochemical demonstration of viral antigen and on the histological brain lesions, Borna disease was diagnosed in a cow and a bull which had suffered from a severe, subacute progressive disorder of the central nervous system. Virus-specific antigen was characteristically localized in neurons, predominantly in the perikaryon and dendrites. In a serum sample available from one of the animals a Borna disease virus antibody titre of 1 in 80 was demonstrated. This is the first report of the natural disease in cattle.