Chronic Wasting Disease Deer tests positive, hundreds more required to evaluate Public meeting scheduled for Tuesday, June 11

A CWD-afflicted white-tailed deer from the front cover of Montana’s CWD Management Plan. Photo by Mike Hopper, Kansas Dept. of Wildlife, Parks, and Tourism.


By Tracy McNew


When Libby’s City Council met on Monday, June 3, it was not an ordinary meeting. An incident command team from Montana’s Fish, Wildlife & Parks, elected officials and a number of  residents filled the room. The main topic of discussion was Chronic Wasting Disease (CWD).

On May 30, FWP announced that tissue samples taken from a sick-looking white-tailed doe killed in the city of Libby had tested positive for CWD. This was the first CWD detection in a wild animal in Montana, west of the Continental Divide.

For FWP, the news was unwelcomed but not surprising. CWD has been in Canada, eastern Montana, Colorado and Wyoming for some time, and the agency was already prepared with a response plan.

CWD is a brain disease that kills deer (mule deer and white-tailed), elk, moose, and caribou. It is a type of Transmissible Spongiform Encephalopathy (TSE) caused by infected proteins called prions that trigger brain and nervous system malfunction. It does not infected humans or other species, but if unchecked, it can lead to large-scale deaths, declines, and eventual extinctions in affected wild game populations.

CWD prions are spread from animal to animal or through soil and plants contaminated with them.

The disease was first noted in captive populations in the late 1960s, but it was soon detected in wild populations and it has continued to spread. CWD cannot be eradicated so FWP’s goal is to manage it.

The disease is always fatal. It takes 1½ to 2 years for symptoms to appear in affected animals, and presently, there is no way to test for CWD in living animals. Test results take approximately two weeks, and eating meat from infected animals is not recommended because CWD prions do not die when meat is cooked. According to the CDC, “no strong evidence of CWD transmission to humans has been reported,” but FWP recommends having your animal tested before consuming the meat.

CWD management includes monitoring the affected populations, and working to keep prevalence low (< 5%) by approving special hunts, management zones, and taking precautions to keep the disease from spreading.

FWP’s first management recommendation for Libby is harvesting 200 deer from within the city and then 200 more within a10-mile radius.