Tracking Chronic Wasting

According to Biff Burton, game warden for Wyoming Game and Fish, this year the agency is taking steps to track the spread of Chronic Wasting Disease, or CWD, a disease that is affecting deer, elk and moose in Wyoming and neighboring Colorado.

The disease is neurodegenerative disorder that attacks the central nervous system of the animals, similar to the way Bovine Spongiform Encephalopathy—otherwise known as BCE or “Mad Cow Disease”—affects cattle.

Like BCE, CWD is also the result of a prion, a very simple infectious agent. Unlike bacteria or a virus, prions contain no DNA or RNA. The prion causes proteins in the brain and other parts of the nervous system to “misfold,” leading to damage to the tissues.

Creutzfeldt–Jakob disease is a human disease caused by prions.

In Wyoming and Colorado, CWD is spreading, Burton said, spurring game and fish officials to begin carefully monitoring animals harvested during hunting season. During hunting season, there will be inspection stations where hunters are required to stop, whether they are on their way out to the field, or back in from the field, and whether they have harvested an animal or not.

If a hunter has harvested an animal, biological samples will most likely be taken, Burton said, so officials can conduct testing to see how CWD is spreading. The samples are generally taken from a particular lymph node near an animal’s larynx, Burton said, so it is helpful to wardens if the animal’s head is retained.

“We take the sample from near the larynx, so it’s best if a bit of neck is still attached to the head,” Burton explained. If WGF employees cannot take a sample from the larynx area of the animal, they will instead take it from the base of the skull.

Testing for CWD is growing in importance, Burton said. Cases of the disease are on the upswing, and the health of Wyoming’s herd is important for future hunting.

And for prion diseases, scientists are still learning about how the diseases are spread. So far, nobody really knows how the disease is transmitted from one animal to the next, making collection of data even more important.

So far, there is no evidence that CWD is communicable between animal and human. However, A study out of Canada showed one instance of a primate who was fed meat from CWD infected animals contracting the disease.

That study, however, is far from conclusive. It has not yet gone through the peer review process and thus should not be considered as gospel. But nevertheless when it comes to humans consuming meat from CWD infected animals, WGF is following the guidelines set by the World Health Organization which recommends humans not consume meat from animals infected with CWD.

Burton, for his part, advises hunters to not take animals that appear to be sick, and strongly suggests that any animal taken be tested for CWD before the meat is consumed.

Testing is available for a fee at the Wyoming State Veterinary Lab in Laramie.