While references to hemorrhagic disease (HD) might seem frequent this fall, there really is no reason for Montanans to be alarmed, according to Montana Fish Wildlife & Parks biologists.

“Not much has changed with hemorrhagic disease,” said FWP Wildlife Veterinarian Jennifer Ramsey. “In Montana, it’s typical for us to see low levels of infection and mortality most years, with a larger outbreak every few to every several years.”

This year happens to be one the larger outbreak years. The outbreak is widespread and a large number of animals – mostly whitetails but also some mule deer and pronghorn – are affected.

Recently, the Fish and Wildlife Commission made a regulation change to limit the number of white-tailed deer licenses in northeast Montana in response to HD outbreaks in the area. And biologists have confirmed cases in every FWP region except Region 3 this year.

“We don’t exactly know why we have larger outbreaks in some years,” Ramsey said. “It’s probably a combination of factors like abundance of the biting midges that transmit the virus, level of previous exposure within the susceptible population of animals and virulence of the particular virus that is circulating.”

Two common types of hemorrhagic disease are epizootic hemorrhagic disease and blue tongue. Both are viral diseases transmitted by biting midges.

Montana has experienced large outbreaks before, but HD itself does not generally cause long-term population declines. Populations generally recover with time unless there are other factors contributing to population declines.

The virus is not infectious to humans. But hunters should always avoid harvesting animals that appear sick. If you do harvest an animal and then suspect it’s sick, you should report that to FWP.

For more information about wildlife diseases and how FWP is responding, check out this article in the current issue of Montana Outdoors.