Evaluating Transmission of Bovine Viral Diarrhea Virus to Cattle by Exposure to Carcasses of Persistently Infected White- tailed deer (Odocoileus virginianus)

Infections with bovine viral diarrhea virus (BVDV) clinically analogous to cattle are described in white-tailed deer (Odocoileus virginianus), but the epidemiologic role of persistently infected (PI) white-tailed deer is unknown. Persistently infected white-tailed deer shed BVDV, maintaining BVDV in groups of deer. Survival of PI white-tailed deer is reduced, and clinically ill or dead PI deer may be a source of BVDV. This study sought to determine if BVDV transmission could occur when cattle come in contact with carcasses of PI white-tailed deer. In two trials, performed in Auburn, Alabama, during November and December 2009, steers were exposed to the carcass of PI fawn A (BVDV 2) or PI fawn B (BVDV 1). Trials were designed with consideration of the influence of contact networks on disease epidemiology, and only one steer from each group was separated into a pen with the carcass. The number of contacts with the carcass was monitored. Following 8 hours, the single steer was commingled with four other steers for 28 days. Animals were tested for BVDV infection. Controls included one steer inoculated intranasally with spleenhomogenate from fawn A, and two steers inoculated intranasally or intravenously with spleen-homogenate from fawn B. Steers in both trials repeatedly contacted the carcasses, but BVDV transmission did not occur. The intranasally inoculated control for trial A and the intravenously inoculated control for trial B became viremic and seroconverted. Although both PI carcasses Evaluating Transmission of Bovine Viral Diarrhea Virus to Cattle by Exposure to Carcasses of Persistently Infected Whitetailed deer (Odocoileus virginianus)