Bovine viral diarrhea (BVDV) causes a variety of symptoms in cattle including no evidence of an effect to severe infections, including diarrhea in calves, and respiratory tract infections. This virus causes economic losses in the cattle industry primary through reproductive losses. Depending on the time of infection during gestation, this virus can cause stillborn young, abortion, birth defects, or a variety of symptoms including fever, discharge from nose and eyes, profuse watery diarrhea, and mucosal lesions.
Persistently infected animals shed large amounts of virus during their lifetime and are the primary spreaders of the virus in livestock. Symptoms of the virus in captive white-tailed deer were similar to that of cattle and captive white-tailed deer have exhibited reproductive failure and birth of persistently infected fawns.
Mule deer are economically important species of big game to most western states, because substantial funds are invested in both hunting and management of those species. Few state wildlife agencies test for the prevalence of BVDV in populations of wildlife, thus the prevalence of the virus in free-ranging populations of wildlife is unknown. We have no knowledge of population level effects of BVDV in wildlife, although we suspect that BVDV may result in lowered productivity. BVDV in wildlife populations not only could transmit BVDV back to domestic stock, but economic losses from BVDV reducing productivity of wildlife populations may be substantial as well.
Our objectives are to learn how the presence of BDVD affects population level performance of wildlife, including survival and recruitment of juveniles. If BVDV in wildlife affects population level processes this information will aid state agencies in managing those populations. This research will also provide information on whether infected animals are viable in wildlife populations and if wildlife populations act as a reservoir for this virus that has the potential to return back to domestic livestock. Understanding those processes and prevalence of BVDV, will provide us with information on the population performance of wildlife and to determine the potential for transmission back to livestock.