Effect of concurrent experimentally induced bovine respiratory syncytial virus and bovine viral diarrhea virus infection on respiratory tract and enteric diseases in calves

Abstract

Concurrent infection with BRSV and BVDV resulted in more severe respiratory tract and enteric disease than did infection with either virus alone, possibly indicating synergistic effect between the viruses. BVDV's role in causing respiratory tract disease is attributable, indirectly, to effects on the host's immune system, not to infection of the lungs.