Epizootic of Hemorrhagic Disease in North Dakota Deer

Abstract

Extensive mortality was observed among white-tailed deer (Odocoileus virginianus), but not mule deer (0. hemionus), in south-western North Dakota during the autumns of 1970 and 1971. It was estimated that at least 2,000 white-tailed deer died during the outbreak. The virus of epizootic hemorrhagic disease (EHD) of deer was isolated from a dead white-tailed deer and considered to be the etiologic agent responsible for the outbreak. Neutralizing antibodies to EHD were detected only in mule and white-tailed deer from the outbreak area. While a significantly higher percentage (P 0.05) of mule deer possessed EHD neutralizing antibodies, there were no differences by age or sex of the deer. The outbreak is discussed in relation to the known epizootiology of EHD. J. WILDL. MANAGE. 37(3):331-335 Beginning in late July or early August of 1970 and lasting until the first week of November, an epizootic of a hemorrhagic disease ravaged white-tailed deer herds in western North Dakota. Geographically, the epizootic area involved included the Little Missouri River drainage and the headwaters of streams to the east of it as well as parts of the lower Yellowstone River that border or are in North Dakota. Within this area, 195 deer carcasses were discovered and it is estimated that this represents not more than 10 percent of the deer which succumbed. Additionally, one sick mule deer and a few sick or dead pronghorn antelope (Antilocapra americana) were also found. The virus of infectious bovine rhinotracheitis (IBR) was isolated from an antelope but not from any of the deer (Richards 1972). During the summer of 1971 additional mortality was experienced within the epizootic area, but of a magnitude that was far less than during the 1970 epizootic. Most of these 1971 losses occurred in individual herds that had probably not been involved in 1970. The 1970 and 1971 die-offs occurred in the same area of North Dakota which experi nced extensive deer and antelope losses in 1962 (Fig. 1) (Richards 1963, 1964). The virus of epizootic hemorrhagic disease was considered to be the etiologic agent responsible for the 1962 epizootic. Tissue and serum samples collected from recently dead deer were submitted to the Department of Veterinary Science at the University of Wisconsin, Madison, for virus isolation studies. Also serum samples collected from hunter killed deer in 1970 and 1971 were tested for neutralizing antibodies to EHD virus and the closely related bluetongue virus (BT). This report concerns the results of these studies. MATERIALS AND METHODS Tissue and serum samples collected from four white-tailed deer found dead of hemorrhagic disease were submitted for virus isolation attempts. First, an attempt was made to reproduce the disease in a 5-month old male white-tailed deer. The liver, lung, and spleen collected from a yearling buck in Billings County within 1 hour after death were inoculated intravenously into the ex1 Research funded by Project W-67-R, Federal Aid to Wildlife Restoration Program. 2 Present address: Veterinary Public Health Section, Florida Division of Health, P.O. Box 210, Jacksonville, 32201. 3 Present address: Dean, College of Natural Resources, University of Wisconsin, Stevens Point, 54481. J. Wildl. Manage. 37 (3):1973 331 This content downloaded from 207.46.13.126 on Sat, 24 Sep 2016 04:50:42 UTC All use subject to http://about.jstor.org/terms 332 HEMORRHAGIC DISEASE IN DEER * Hoff et al. 1 2 3 4 6 7 a 13 10 11 12 13 14 15 16 17 is 19 21 22 3 24 2 2 b V A 29 3D 3 1 32 CAMT.1)II I 1 LlIn I w ln Ia ? ~ In Il r NES I 1 III L?lr II )1 L?r I I) ?L ll ? ) CWAN 31 .1-L n ?I L C1 ?I ???I 1I 111 1? 1 A 111 I . n L ~ LI l ?? ? I? U ~ I -1 11 CY LIl In~??n r ~ II In ?~I rl Irr u ?A