EHD cases confirmed in deer found southeast of Lewiston

The Idaho Department of Fish and Game has confirmed an outbreak of epizootic hemorrhagic disease in Game Management Unit 11 southeast of Lewiston.

According to a news release from the agency, the disease often called EHD was confirmed in one whitetail deer and two more animals at the same location are suspected of having died from it. The department has reports of deer displaying EDH-like symptoms in Unit 8 near Potlatch and Unit 8A near Kendrick.

EHD often pops up in late summer and can persist until temperatures drop low enough for one or more hard freezes. During widespread outbreaks, it can kill many thousands of animals. For example, in 2003 and 2021 the disease killed 5,000 to 10,000 whitetail deer.

It is spread by biting midges, also known as no-see-ums. The insects breed in mud near watering holes like stock ponds. During hot and dry summers, deer are often attracted to watering holes where the midges are found.

Animals with the disease are disoriented, weak and often congregate and die in or near water as they seek relief from fevers. They may drool, have labored breathing, swollen tongues or heads, and show no or little fear of humans. Infected deer often die within 24 to 36 hours.

It is not transferable to humans or pets and poses little risk to livestock, according to the news release.

Whitetail deer are the most common victims of the disease but it can affect mule deer and elk, though those animals are not as prone to it, according to the news release.

There is no treatment for the disease and no way to significantly reduce the midge population.

The agency is monitoring the outbreaks and has not altered any planned hunting seasons or regulations. According to the news release, deer that recover from EHD are safe to eat but animals that are ill should be avoided.

The disease can cause significant declines in local populations of whitetail deer. However, herds can recover quickly. More information can be found at Fish and Game’s Wildlife Health webpage at idfg.idaho.gov/species/whl/report or by contacting the department at (208) 799-5010.