Investigation into Bovine Viral Diarrhea (BVD) in a Group of Scimitar-Horned Oryx (Oryx dammah): Diagnosis of a Transient Infection with Bovine Viral Diarrhea Virus 1 Strain Singer Arg
Bovine viral diarrhea (BVD) is a contagious disease of cattle and other ruminants caused by an RNA virus of the genus Pestivirus.1,2 Domestic cattle are considered the reservoir for BVD. The virus is shed in feces and nasopharyngeal secretions and infection occurs through ingestion or potentially inhalation. In domestic cattle, BVD most often causes subclinical infections including pyrexia and leukopenia with an appropriate immune response, although severe infections and herd outbreaks are common.1
A Scimitar-horned oryx calf with chronic diarrhea and suspected lack of passive transfer (LPT) was diagnosed with BVD-1, strain Singer-Arg through whole blood and fecal polymerase chain reaction (PCR). Successful therapy included two plasma transfusions and supportive treatment. A second calf was positive through PCR on whole blood but was asymptomatic. Fecal PCR for BVD in this animal was negative. Complete evaluation of the entire herd of Scimitar-horned oryx, consisting of whole blood PCR, fecal PCR and immunohistochemistry of pinna tissue specimens were negative. Additionally, banked sera samples for BVD from common eland (Taurotragus oryx), new additions to the herd, were negative.
It is difficult to assess the role, if any, of BVD in this population; but it seems likely that at least a transient infection was present in the group and may be detectable during calving. In this particular calf, a lack of maternal antibodies may have predisposed to clinical infection with BVD. Continued surveillance for BVD virus in exotic hoofstock, especially those species considered for repatriation programs, is warranted.
1. Heuschele, W.P. 1993. Bovine viral diarrhea-mucosal disease. In: Howard, J.L. (ed.). Current Veterinary Therapy: Food Animal Practice (No. 3). W.B. Saunders, Co., Philadelphia, Pennsylvania. Pp. 432–434.
2. Van Campen, H., J. Ridpath, E. Williams, J. Cavender, J. Edwards, S. Smith, and H. Sawyer. 2001. Isolation of bovine viral diarrhea virus from a free-ranging mule deer in Wyoming. J. Wildl. Dis. 37: 306–311.