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‘Zombie deer disease’ is in Wyoming. It’s in Montana. How Idaho plans to keep it at bay

Monitoring Idaho’s mule deer

Idaho Fish and Game biologists trap, collar and monitor Idaho's mule deer in order to manage them. Video courtesy of Idaho Fish and Game
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Idaho Fish and Game biologists trap, collar and monitor Idaho's mule deer in order to manage them. Video courtesy of Idaho Fish and Game

The last few months of 2018 saw an increase in reports of a highly contagious, fatal deer disease in states neighboring Idaho. Soon, the Idaho Legislature will decide whether to approve further restrictions that may help keep the illness from spreading across state lines.

Chronic wasting disease, first found in captive mule deer in Colorado in the 1960s, is a disease of brain proteins called prions — similar to mad cow disease. Sometimes called “zombie deer disease,” the illness causes deer species, including mule deer, whitetail deer, elk and moose, to stagger, drool and lose weight until they eventually die.

Idaho has never had a reported case of chronic wasting disease, and wildlife management officials have spent years ensuring things stay that way. Idaho Fish and Game has randomly sampled roadkill and harvested animals since 1997, and it tightened restrictions last summer to ban the import of cervid (deer, elk and moose) carcasses from other states (with some exceptions), as well as the use of natural cervid urine as an attractant.

But some of the new regulations Fish and Game commissioners voted for last July must still be approved by the state legislature. The 2019 session began Monday; the Fish and Game regulations have not yet been scheduled for a vote.

If approved, the additional rules would:

  • ban the import of live mule deer, white-tailed deer and moose

  • take chronic wasting disease risks into consideration for Fish and Game winter feeding plans

  • restrict the public from winter feeding deer and elk in the event chronic wasting disease is discovered in Idaho

One of the proposed rules relies on the possibility that zombie deer disease makes its way to Idaho. Some experts believe it’s an inevitability.

“The likelihood is very high that sooner or later that CWD will infect our herds in Idaho,” Fish and Game Commissioner Dan Blanco told the Lewiston Tribune in 2017. “Having said that, I think what we need to do is try to stave off that day as long as possible and once it does enter the state, do everything we can do to contain it.”

Centers for Disease Control and Prevention

Each year, Idaho Fish and Game samples roadkill and harvested animals in hunt units bordering Wyoming, one of places hit hardest by chronic wasting disease. Idaho’s Bonneville County landfill, which handles trash from nearby Teton County, Wyoming, recently decided it wouldn’t accept roadkill carcasses from Wyoming. Chronic wasting disease was confirmed in Teton County in November.

Montana saw an uptick in confirmed cases of chronic wasting disease last year, with two confirmed cases in November and 16 more in December. For the past two years, Idaho’s random sampling schedule has included only one area that borders Montana. From 2019-20, Fish and Game will test the panhandle, and from 2020-21 it will test Central Idaho.

“The closest incidence [of chronic wasting disease] in Montana is still over 100 miles away from us,” said Roger Phillips, spokesman for Idaho Fish and Game. “Where some of the reports in Wyoming have been less than a mile [away].”

Disease passes easily between animals through contact with infected feces, urine or saliva and can incubate for up to 24 months before symptoms present. The disease can survive in the environment for years, infecting more animals indirectly.

Chronic wasting disease has not been linked with its equivalent in humans, Creutzfeldt-Jakob disease, but health experts believe there’s still a potential risk in eating meat from infected animals. The Centers for Disease Control and Prevention recommend minimizing exposure to animals that may have chronic wasting disease. Find more guidelines here.

Nicole Blanchard is the Idaho Statesman’s outdoors reporter. She grew up in Idaho, graduated from Idaho State University and Northwestern University and frequents the trails around Boise as much as she can.