December 2017 Edition | Volume 71, Issue 12
Published since 1946
What Hunters Can Do to Stop Chronic Wasting Disease
As more than 11 million hunters slip into the woods to enjoy the bounty of our nation’s wildlife resources, they likely hear about a sometimes vague, and always concerning disease affecting deer, elk, and moose: Chronic Wasting Disease (CWD). Although scientists have known about the disease since the 1960’s and have been actively managing it for more than thirty years, CWD still manages to cultivate uncertainty, concern, and sometimes, downright paranoia.
If you are one of the fortunate who will pursue some or all of North America’s unique members of the deer family, it’s important that you know not just the facts about CWD, but also how you can help wildlife managers control or avoid CWD in the states that you hunt.
Let’s start with the facts. Here is what you need to know:
- CWD is an always-fatal nervous system disease found in cervids (deer, elk, and moose). It can be transmitted through direct animal to animal contact, contact with saliva, feces, carcass parts of an infected animal, and can even spread through soil that has been contaminated with any of the above tissues or fluids.
- The disease is not caused by a virus or bacteria. CWD is one of a family of diseases called transmissible spongiform encephalopathies. These diseases are the result of a naturally occurring protein, called a prion, that becomes misfolded and thus resists being broken down by the body the way normal proteins are. When these misfolded proteins are introduced into a healthy cervid, they multiply by causing the animal’s normal and healthy prion proteins to misfold and begin damaging the animal’s nervous system. This process may take as long as two years before the animal begins to show outward signs of the disease.
- There is no known cure. CWD, like all transmissible spongiform encephalopathies, is not treatable and ultimately fatal. This makes it a real, and undeniable threat to animal and herd health. To date, scientists have documented that CWD can have negative population effects in elk, mule deer, and white-tailed deer. In Wyoming, where little active management of the disease has been done, published models predict that CWD has a population level impact when its prevalence within the herd exceeds 27%, and herds in some areas of the state are currently infected with CWD at rates higher than 40%.
- You will likely never see animals exhibiting symptoms of CWD. Animals in the late stages of CWD are often emaciated, show erratic behavior, and exhibit neurological irregularities. However, due to the long, slow advancement of the disease, infected animals are almost always killed by predators, vehicles, or other disease well before symptoms of CWD get bad enough for a human to recognize. This is also a good reason why you should get your harvested animal tested, even if it appeared healthy when you harvested it. Additionally, you should become aware of your states’ regulations to know how to report a sick animal if you ever encounter one. Some states offer replacement licenses for hunters that harvest a CWD infected animal, some states will authorize you to remove a sick deer and submit it for testing, while still other states mandate that only their staff respond to reports of sick animals.
- CWD has not been shown to be infective to humans. Current research indicates that there is a robust species barrier that keeps CWD from being readily transmitted to humans. In fact, there are several other species that don’t seem to contract CWD either, like cattle and pronghorn. However, laboratory studies have shown that the CWD infective prions can be forced to morph into a form that may be infective to human. So, you should be informed on how to prudently handle an animal that you may be lucky enough to harvest this fall.
What Should Hunters Do?
Hunters are one of conservation’s greatest tool for wildlife management, and particularly so to the management of CWD. Samples collected from hunter-harvested cervids (deer elk or moose) are the key to understanding and controlling the spread of CWD. Here’s what you can do to help:
- Know the status of CWD regulations where you hunt, as well as the states you will travel back through with your harvested animal, and follow them carefully. Do not move carcasses or carcass parts from one area to another. Transportation of live animals, infected harvested animals or parts of infected animals is an easy way for CWD to arrive in your neighborhood. Please check with your state fish and wildlife agency on what parts of your harvested animal you are allowed to bring back to your home.
- If the state you’re hunting in is testing for CWD in cervids, then you can help by submitting your harvested animals for testing. Since the odds of finding an infected animal are low, obtaining high numbers of samples is necessary to learn if the disease is present. Testing for CWD will also allow you to avoid eating infected animals. Although no linkage between CWD and human infection has been made, scientists recommend against eating CWD-positive game.
- Dispose of the remains of all harvested animals in a way that reduces the chance of spreading CWD. Burning or chemical treatment will not destroy the infective prions, and throwing a carcass or remains out in a back field for scavengers will only contaminate the site if the animal was CWD positive. Check with your state fish and wildlife agency on the proper method of disposal.
- For many hunters, success sometimes means shooting the biggest or largest of the species. For others, success is obtaining meat for the freezer. Biologists strongly recommend that you consider adding disease prevention to your measures of success to ensure the future of our deer hunting traditions. Since the older an animal is, the higher chance it has of contracting, and thus spreading CWD, this means harvesting younger animals and more does is the best thing you can do to both fill your freezer and stop CWD
- Don’t use animal attractants such as grain, other animal feed, or lures to concentrate animals for the purpose of improving your success hunting or observing animals. These and other wildlife feeding practices enhance the risk of transmitting CWD. Remember, CWD can be spread by, 1) animal to animal contact, 2) saliva, feces, and perhaps urine, 3) contaminated soil (presumably from the prions being shed via saliva and feces). So, it’s reasonable to assume that any factor that causes animals to come into contact with each other at a higher frequency, a higher density, and a prolonged period of time increases the probability that CWD will be transmitted. Also, since infectious prions can persist in the soil and can even be taken up by plants, continuing to concentrate animals in one spot only worsens the risk of spreading CWD. This may change the way you hunt, but CWD is indifferent to tradition.
- Follow guidelines for field-dressing and processing harvested animals in CWD-positive areas.
- If the state agency is using sharpshooters to reduce deer numbers in your area because of specific knowledge of the harvest location of infected animals, please grant them access to your property or consider getting additional permits to harvest animals with a higher probability of infection.
If we are to preserve our traditions of hunting deer, elk, or moose, we need to recognize that CWD is a serious threat to the future of these animals in North America. The most important things you can do are follow regulations concerning CWD, safely handle harvested animals, and get your harvested animals tested. Enjoy your hunt and be a true conservationist by fighting CWD!