In recent weeks, laboratory tests confirmed epizootic hemorrhagic disease and bluetongue virus in white-tailed deer in North Idaho. Deer from the Clearwater Region tested positive for EHD, while deer from the Panhandle Region tested positive for both diseases.
According to Fish and Game, the two diseases are different, but they are closely related. Both are a type of hemorrhagic disease spread by small biting flies, known as midges, which reproduce in and around warm, stagnant water. This summer’s conditions likely created situations where midge populations “boomed” around limited water sources, leading to increased risk when deer gather at them.
Hemorrhagic disease outbreaks occur periodically in the Clearwater and Panhandle regions, often during hot, dry summers. In northern states and other regions where hemorrhagic disease is less common, deer have little to no immunity to the virus.
It is difficult to estimate how many deer are being affected in Idaho, but the number of reports received is currently less than 200 in the Panhandle and less than 600 in the Clearwater.
Outbreaks can generally be expected to continue until cool, wetter weather arrives or after a hard frost occurs and kills the midges that spread the disease. Fish and Game staff will continue to monitor the situation.
People are asked report sick or dead deer online via the Wildlife Health Reporting page or by calling the Clearwater Office at (208) 799-5010. Public reports are vital in tracking the impact of hemorrhagic diseases on deer populations.
