EHD Confirmed in Deer Mortalities on Flathead Reservation
Wildlife officials have confirmed the presence of Epizootic Hemorrhagic Disease (EHD) in deer found deceased on the Flathead Reservation in northwestern Montana.
This viral disease is known to cause sudden and significant die-offs, particularly during late summer and early fall when biting midges, the disease’s primary vectors, are most active.
Weather and Environmental Factors
Northwestern Montana is currently experiencing a weather alert for winter-like conditions, with cold temperatures anticipated across the region today. Such rapid shifts in temperature can influence disease dynamics among local wildlife populations.
Cold snaps may reduce midge activity and thus limit further transmission of EHD, but deer already exposed to the virus often succumb quickly due to its hemorrhagic effects.
Expert Perspective
Montana Fish, Wildlife & Parks (FWP) and the National Park Service are monitoring the situation closely. EHD outbreaks often follow patterns tied closely to ecological conditions and insect vector populations.
As a highly contagious and often fatal viral disease, EHD affects white-tailed and mule deer. The virus causes blood vessel damage leading to swelling, internal bleeding, and severe dehydration.
These symptoms rapidly deteriorate the health of infected deer, frequently resulting in death within days. Surveillance and reporting remain critical in managing this wildlife health concern.
Biological Context
- EHD is transmitted by biting midges (Culicoides spp.) that thrive in warm, moist environments.
- Deer infected with EHD generally exhibit swelling of the head, neck, and tongue along with nasal discharge and lethargy.
- Outbreaks tend to occur annually but severity varies depending on climatic and environmental conditions affecting midge populations.
- This disease does not affect humans or domestic animals but can cause local population declines in affected deer herds.
Monitoring efforts on the Flathead Reservation will continue to assess the extent of the outbreak and inform wildlife management decisions in Montana’s deer populations.
Additional reporting and sources from: EHD confirmed in deer deaths on Flathead Reservation | Montana News | montanarightnow.com
