A highly infectious disease that kills deer and elk is inching closer to Missoula.
The Confederated Salish and Kootenai Tribes (CSKT) reported on Friday, Jan. 24 that a mule deer shot on the northern portion of the reservation has tested positive for chronic wasting disease.
The deer was shot on the Hog Heaven management unit west of Flathead Lake near Elmo and CSKT Fish and Wildlife staff sent a brain sample to the State Laboratory. The laboratory released the positive results on Jan. 6.
Chronic wasting disease (CWD) was first detected in Montana in 2017 as the disease moved up from Wyoming, although diseased herds in the Dakotas and Alberta, Canada, also threatened to invade Montana.
Unlike most diseases that are caused by bacteria or viruses, CWD is caused by a protein called a prion that animals can pick up if they have direct contact with other infected animals, animals that died of the disease or even saliva or other bodily fluids left in the environment by infected animals.
The disease is degenerative and fatal over one to two years, killing all members of the deer family, including elk and moose. The name comes from the appearance of symptomatic animals, which become emaciated and sick-looking in the last stages of the infection before they die.
Because it can’t be treated with vaccines or antibiotics, there’s no way to eliminate the disease and biologists can only try to prevent the disease from spreading.
However, that’s not been successful in Montana. After the disease became more prevalent in southwest Montana, it suddenly showed up in northwest Montana near Libby.
It’s believed that a hunter shot an animal in southwest Montana and took it back home to Libby where the carcass was dumped, leading to other animals becoming infected.
Since Montana Fish, Wildlife & Parks started sampling hunters’ animals for CWD in 2017, the disease has been detected in clusters in the southeast, especially along the Beartooth Mountain front, along the High Line east of the Rocky Mountain Front and around Libby and Dillon.
But this past October, one sample tested positive north of Kalispell, and now there’s one farther south on the Flathead Reservation. Experts warn that the disease could already have spread to other areas where it’s yet to be detected. So they urge people to take precautions.
In mule deer tested in 2021 through 2023, the disease prevalence rate varies from 1% to 19% depending on the location. For white-tailed deer, the prevalence rate varies from 1% to 30% with the highest prevalence around Dillon.
The CSKT Wildlife Program is implementing its initial response according to its CWD Surveillance and Management Plan, which includes collecting samples from 150 mule deer in the Hog Heaven and adjacent Irvine hunting units to try to determine the disease prevalence.
They’re asking tribal hunters for help harvesting the deer but warn that any animal that tests positive for CWD should not be consumed. There has been no known transmission of CWD to people however, that could change if the prion mutates.
“Under these circumstances, we advise all CSKT hunters on the Flathead Reservation to get all big game animals tested for CWD and wait for test results before you process further or move the carcass for processing. Protect the carcass from contact with other animals. Please stop at any hunter check station you see for testing. DO NOT dump carcasses anywhere on the Reservation. Carcasses can be disposed of at the Polson Transfer station, or put the hide and bones in plastic garbage bags and dispose of them as household trash,” according to a CSKT release.
Contact reporter Laura Lundquist at lundquist@missoulacurrent.com.
