FWP cautious about disease spread

Two white-tailed deer killed in Libby recently have tested positive for Chronic Wasting Disease (CWD), and local Fish, Wildlife & Parks (FWP) staff say there are steps hunters can take to slow the spread of the disease.

FWP Biologist Bruce Sterling said hunters need to be responsible when they dispose of carcasses, as CWD is spread not only by animal-to-animal contact but can also be spread through contaminated grass and soil. “This is a new endeavor for hunters,” he said. “You can’t just dump carcasses.” Hunters need to be responsible and do what they can to prevent the spread of the disease, he added. FWP recommends dumping carcasses at a landfill instead of in the woods. If a hunter kills an animal with CWD that appears to be healthy, the disease can affect the environment where the carcass is disposed for more than two years after, according to FWP, so it’s best to be safe and dispose of carcasses at a landfill.

Sterling said that FWP has been testing animals for CWD since the 90s, with the disease being found in North Dakota, South Dakota, Wyoming and Alberta, Canada. The first case in Montana was discovered in October 2017 and since then has been detected in Carbon, Liberty, Hill, Blaine, Phillips, Valley, Daniels, Sheridan and now Lincoln counties. When CWD is found, FWP establishes CWD Management Zones. Whole carcasses, whole heads or spinal columns from any deer, elk, or moose harvested cannot be removed from these zones unless the animal has tested negative for CWD.

In the case of the Libby deer, FWP’s CWD response plan includes a roughly 10-mile radius from where the deer was collected. The agency will collect samples from road-killed deer in the surrounding hunting districts to determine the prevalence of the disease. Sterling said there are no plans to test deer in Sanders County at this time. If FWP does decide to collect samples in the future, they will make hunters aware of any requirements.

Sterling said there is no evidence that CWD can cross species and affect humans. It’s a neurological disease, not a virus or bacteria as some people suspect. CWD is a progressive, fatal disease affecting the nervous system of mule deer, white-tailed deer, elk and moose. It is part of a group of diseases called Transmissible Spongiform Encephalopathies (TSEs). TSEs are caused by infectious, mis-folded prion proteins, which cause normal prion proteins throughout a healthy animal’s body to mis-fold, resulting in organ damage and eventual death. Sterling said an affected animal will be skinny, lethargic, drooling and almost emaciated. He said it’s hard to detect, and FWP tests for the disease by harvesting lymph nodes from animals.

Sterling said it’s similar to mad cow disease in cattle, scrapie in sheep and Creutzfeldt-Jakob disease in humans. CWD is a slow-moving disease. However, left unmanaged, it could result in long-term population declines within affected herds. “It’s certainly something we don’t want,” Sterling stated. “We’ll do everything we can to try to prevent it. We need hunters to be cautious and stop dumping carcasses to prevent the spread.”

For more information about CWD in Montana, visit fwp.mt.gov and click on “Chronic Wasting Disease.”