Experimental infection of deer with bovine viral diarrhea virus.

In order to determine the susceptibility of deer to infection with bovine viral diarrhea virus (BVDV), four mule deer (Odocoileus hemionus) fawns and one white-tailed deer (O. virginianus) fawn were inoculated intranasally with the New York-1 strain of BVDV originally isolated from cattle. None of the animals developed clinical signs of illness. Virus was isolated from white blood cells from four fawns on one or more occasions from day 2 through day 15 post-inoculation (PI) indicating that infection and systemic spread of BVDV had occurred. In addition, virus was isolated from nasal swabs from three fawns, one to three times, from day 2 through day 8 PI. Four fawns had virus neutralizing antibody titers to two strains of BVDV prior to inoculation and all developed greater than four-fold increases in virus neutralizing antibody titers by 3 wk PI. No gross lesions of bovine viral diarrhea were detected at necropsy approximately 3 mo PI. A variety of nonspecific lesions were detected by histopathology. Based on these findings, mule and white-tailed deer are susceptible to infection with BVDV. Isolation of virus from nasal swabs is evidence that BVDV could be transmitted by deer via direct contact.