CODY- Wyoming Game and Fish biologists have confirmed that epizootic hemorrhagic disease (EHD) has killed a number of white-tailed deer and some pronghorn in the Big Horn Basin, Sheridan and Casper areas this year.
Samples from approximately 13 white-tailed deer and four pronghorn were collected and sent to the Game and Fish laboratory in Laramie, WY where lung and spleen tissues were tested for hemorrhagic disease--either epizootic hemorrhagic disease or the bluetongue virus. The test results indicated that EHD was the cause for two of the four pronghorn deaths and six of the 13 white-tailed deer. To date, bluetongue virus has not been isolated or detected.
Reports of carcasses along the Tongue River, Little Powder River, Greybull River, Shell Creek and other drainages were received during mid-August and September. "Conditions were ideal for an outbreak of the disease during late summer," said Cynthia Tate, Assistant Veterinarian for the Game and Fish. "Recent cold temperatures should slow the spread of the disease as temperatures affect the ‘no-see-um' gnats—the agents responsible for disease transmission."
According to Tate, when first infected an animal looks healthy and normal. As the disease progresses the animal begins to look weak and ill. The EHD virus can cause spontaneous hemorrhaging in the muscles and organs five to 10 days after an animal is infected. Even with a hard frost the disease may continue to claim some animals that were previously infected for a couple of weeks.
The last significant outbreak of the disease in the Big Horn Basin was in 2007 and the one previous to that was in 2001. "In both of those years in the basin, numbers of white-tailed deer were reduced significantly, however, this outbreak does not appear to be as severe," said Tom Easterly, the Game and Fish wildlife biologist in Greybull.
"We collected samples from the Gillette, Leiter, Kaycee, and Powder River areas this year. The outbreak appears to be localized, but widespread through various parts of our region," said Lynn Jahnke, Sheridan wildlife management coordinator for the Game and Fish. In the Sheridan area, the most recent outbreak occurred in 2006 and the one previous to that was in 1998.
Hunters do not have to worry about getting the disease from eating deer meat. "There is no human health concern from the hemorrhagic disease," Tate said. "Humans can't get it and neither can most other wildlife."
She added that mule deer occasionally get the disease but are generally insulated from the infection because they don't tend to inhabit the environment of the gnats.