Multiple Viral Infection in Calves with Acute Bovine Respiratory Tract Disease

Abstract

SUMMARY Nasal secretions and blood samples were collected on 1 farm from 12 beef calves affected with acute bovine respiratory tract disease. Nasal swab eluates were inoculated into tube cultures of primary bovine embryonic kidney ( bek ) and primary bovine testicle ( bt ) cells. Parainfluenza-3 ( pi -3) virus was isolated from 7 calves, noncytopathogenic bovine viral diarrhea ( bvd ) virus was isolated from 3 calves, and rhinoviruses were isolated from 2 calves. Multiple viral infections, as evidenced by viral isolation or by significant increases in serum antibody concentrations during the epizootic, were observed in several calves. Both pi -3 virus and a rhinovirus were isolated from the nasal swab eluate of 1 calf. The number of viral isolations in bek cells was not increased by the use of roller cultures or lower (34 C.) incubation temperatures.