As hunters around the country draw nearer to their respective hunting seasons, it’s inevitable that we refocus on our hunting regions and conservation issues. Chronic wasting disease (CWD) is a term many hunters are vaguely familiar with, but how much do you actually know about the disease and its spread throughout the U.S.?
A neurodegenerative disease resulting in abnormal behavior, loss of body condition and eventual death, CWD is a prion disease with a non-living disease vector—the infamous “Mad Cow Disease” is bovine spongiform encephalopathy, another prion disease. Prions are an abnormal form of a typically-harmless protein found in the brain and are responsible for a variety of neurodegenerative diseases in both animals and humans. These diseases occur when normal protein folds and “clumps” in the brain, causing brain damage. Scientists are still uncertain what causes the clumping, and the disease is almost impossible to test for in living animals; many diseased cervids (members of the deer family) may show no signs of the disease for several years yet still actively be spreading CWD.
Transmission of CWD is thought to be lateral—passed from animal to animal, not from mother to fetus—and can occur through direct contact via saliva, blood, urine and feces, or indirectly through the environment: water, food and even the soil.
CWD has been identified in 25 states and continues to spread. So what does this mean for hunters, and how do we prevent its continued transmission? Dr. John Fischer, Director and Professor at the Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, The University of Georgia, boils it down simply: “Prevention is the only truly effective method for managing chronic diseases in wild populations. Period.”
Hunters in non-CWD areas can hunt responsibly when traveling in CWD areas—process your animals appropriately and move the meat responsibly. Remember even a seemingly healthy deer can test positive for CWD—the Quality Deer Management Association (QDMA) notes that most hunters will never see a deer showing classic symptoms of CWD, as animals typically die from a variety of indirect causes before exhibiting evidence of the disease. And remember to test more than just your deer: CWD is found in most cervids, including elk, moose, mule and white-tailed deer—and is 100% fatal to all deer species.
Hunting in a known CWD area? Practice patience. Test your game for CWD and wait for the results before eating. There are a limited number of labs that can run the correct tests, so this could mean a waiting period of up to several weeks for results, but it is important to have the test results in hand before meat consumption. The Centers for Disease Control (CDC) is actively looking for the disease in humans (and has been for several years) and to date there have been no known cases of CWD in humans, but their official statement is “no consumption of CWD-positive meat.” No one is certain how the disease would manifest in humans, and some scientists speculate cases could be present that have not yet been identified as linked to CWD.
When asked about the possibility of CWD in humans, Dr. Krysten Schuler, Wildlife Disease Ecologist in the Animal Health Diagnostic Center at Cornell University, noted, “I don’t think we should just write it off and say it’s not a possibility. I’m a prevention person. There are possibilities where we would be worried about it.”
For his part, Dr. Fischer is a hunter living in a known CWD area. He actively hunts, and does consume deer meat from CWD areas, but only after it has tested negative for the disease.
So what does CWD management look like? Dr. Jonathan Mawdsley, Science Advisor for the Association of Fish and Wildlife Agencies, notes that currently, “CWD response belongs to the states.” Federal aid would be helpful, certainly, but is not likely to occur in the near future. States need increased funding for research and testing—resources are fairly minimal currently, and the number of labs who can run the required testing is limited. State wildlife agencies are able to direct hunters to the best lab for testing.
There are biological, economic and social sides to the disease, and there is no easy answer. State wildlife agencies will always draw contention but often work to create management tactics that work for hunters, not to hunters — the long-term good of the resource and the sportsman is continually considered. Many states with CWD are not seeing a subsequent decrease in hunting license sales; Wyoming, for example, is seeing as much as a 20% uptick in license sales in the past few years, notes Scott Talbott, the Director of the Wyoming Game and Fish Department.
However, hunting in a CWD-positive region should change hunter behavior. Hunters should always have deer tested before consuming meat and should avoid transporting whole, intact animal carcasses and trophy heads from CWD-positive areas. Consider alternatives to natural deer urine-based lures, and report any odd deer behavior to state wildlife agencies.
When breaking down a deer, bone out the animal, taking extra care around the high-risk tissues where CWD prions accumulate: eyes, neck lymph nodes, brain, tonsils, backbone, intestinal tract and spleen. Bag the carcass and dispose of it in the trash or landfill—burning, rendering or composting carcasses will not break down infectious CWD prions. Hunters should take these precautions even if the deer you’ve harvested from a known CWD area looks healthy—animals can be infectious while still outwardly appearing healthy and normal. And always have the meat tested before consumption.
Once established in an area, CWD looks like it’s going to be there, surviving in the deer, the water—even the soil itself. The most effective way to manage is containment—to never let the disease beyond the areas where it exists already. Avoiding the transportation of diseased game will go a long way in this prevention.
“The need to keep it out of areas where it’s not is the most effective way to manage it,” commented Matt Dunfee, the Director of Special Programs for the Wildlife Management Institute and CWD Alliance.
Not sure if CWD has been found in your area? Earlier this autumn, we partnered with the QDMA to release a layer in the onX Hunt App that helps hunters identify where CWD is present. The QDMA team has also compiled a large amount of information on the disease and how it applies to hunters as well as herd management techniques.
Find more information on the onX / QDMA CWD Layer here.
header image: Sam Soholt