Idaho Fish and Game officials on Tuesday put the estimated number of whitetail deer dead due to the viral disease, bluetongue at 1,000.

Fawn whitetail deer. Image/Lynn Betts, USDA Natural Resources Conservation Service.
Fawn whitetail deer. Image/Lynn Betts, USDA Natural Resources Conservation Service.

Bluetongue is transmitted the same way as Epizootic Hemorrhagic Disease (EHD) and is a similar disease. Neither poses a threat to humans. Gnats transport the virus from animal to animal. Outbreaks become more severe during hot, dry summers when animals congregate around water sources with muddy shorelines that are prime breeding ground for gnats.

The disease has hit whitetail herds in the Grangeville, Whitebird, Harpster, Juliaetta, Kendrick, Troy, Deary and nearby areas this summer.

Bluetongue is less common than EHD, but it’s found in livestock throughout the Great Basin, although rarely fatal to livestock, according to Mark Drew, Fish and Game’s state wildlife veterinarian. Drew noted that deer that have survived past EHD outbreaks build immunity to the disease and pass that immunity to their offspring, but exposure to EHD does not make them immune to bluetongue.

The Clearwater area had a large-scale outbreak of EHD in 2003, and Fish and Game officials estimated up to 10,000 whitetails died.

It is difficult to get the exact number of diseased or dead animals, but the outbreak is not expected to significantly reduce whitetail populations, or affect hunting season that opens Oct. 10.

This year’s outbreak is not expected to be anywhere near 2003 in terms of deer die offs, and neither bluetongue nor EHD has long-term, significant population impacts on white-tailed deer. Idaho’s whitetail populations are high, and hunters will find deer, but the outbreak could affect local herds.

The outbreak typically winds down when the first hard frost kills the gnat population.