EN
The aim of the study was to identify, using serological and virological tests coupled with RT-PCR, animals in a herd suspected of infection with bovine viral diarrhea virus (BVDV). All the animals, except two, were seropositive for BVDV in a group of 26 herd-mates. One animal showing a slow growth rate and pulmonary infection was suggested to be possible persistently infected with the virus. Three consecutive antigen-detecting tests done on serum samples within three week period gave positive results. Thus, the slow growth rate and susceptibility to respiratory tract infections in a single animal coupled with high prevalence of seropositive animals in a herd are good indicators of possible circulation of BVDV. Both clinical examination and laboratory testing proved useful in the identification of a single virus shedder in a suspected herd.