HERE’S WHAT YOU NEED TO KNOW
- CWD is an always-fatal nervous system disease
found in cervids (deer, elk, moose, reindeer). 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. To date, it has been found in wild or
captive cervids in 33 states, 5 Canadian Provinces, Norway, and South
Korea.
- 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 is 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. Published models predict that CWD has a
population level impact when its prevalence within the herd exceeds 27%, and in
areas where little active management of the disease has been done, herds 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, hunters, or other diseases well before symptoms
of CWD get bad enough for a person to recognize. Be aware of your states’
regulations to know how to report a sick animal if you ever encounter one. Refer
to your state fish and wildlife agency’s CWD website for more information.
- 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 humans, and it has been shown
that other primates (macaques) can contract the disease by consuming meat from
CWD infected deer. Therefore, it is recommended that humans not consume meat
from infected animals.
- The best way to manage CWD is to prevent its
introduction into new areas and limit its spread. To date, CWD has persisted,
spread, and increased in prevalence in nearly every area where it has been
introduced. Since there is no vaccine for a prion disease like CWD, the options
for managing CWD are extremely limited. The most effective strategies, by far,
are those that eliminate ways CWD can travel to new areas by infected animals
or infected animal parts. Ideally, there should be no animals moving from
infected areas to uninfected areas. In places where CWD is present, cervid
populations should be managed to reduce their potential to congregate or
increase in unnaturally high numbers.
WHAT SHOULD YOU DO ABOUT IT?
If you're a wildlife enthusiast...
- Get Involved. CWD is an incredibly difficult disease to manage due to its tenacious persistence in the environment, its ease of transmission, its long incubation period, and its difficulty to detect in infected animals. Therefore, the management of this disease demands significant resources and often requires drastic and long-term measures (culling, increased hunter harvest rates, etc.). Your voice is needed to support the agencies and biologists tasked with fighting this disease by advocating for funding and science-based tactics for CWD control.
- Think about how your actions might spread CWD. Remember, CWD can be spread by, 1) animal to animal contact, 2) saliva, feces, and perhaps urine, and 3) contaminated environments (presumably from the prions being shed via saliva and feces). So, any factor that causes animals to interact with each other at a higher frequency, a higher density, and a prolonged period of time increases the probability that CWD will be transmitted. Do not feed, bait, or attract cervids to your or your neighbor’s property, and if you live in a state or area where such practices are prohibited by law, report any of this behavior to your local wildlife official.
- Help wildlife managers. Although rare, there have been several cases where CWD positive animals have been identified by a concerned wildlife watcher. If you observe a cervid showing emaciation, drooling, or staggering movement, call your state fish and wildlife agency. Remember, these symptoms can be caused by several other wildlife diseases so if you see them, don’t assume CWD is the cause, but also don’t hesitate to contact your local wildlife officials.
- Stay educated and help educate others. Be aware that much of the information about CWD readily available on the internet and in popular media is incomplete, heavily biased, or abjectly false. Fortunately, there are numerous sources of reliable, science-based information available to the interested wildlife enthusiast. Nearly every state fish and wildlife agency currently managing CWD has an information website where you can learn about what is happening with the disease in your area. These pages can be found by clicking on a state in the interactive map found at the CWD Alliance website. Additionally, both the U.S. Geological Survey National Wildlife Health Center and the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service have information websites that host valuable CWD information.
If you're a hunter...
- 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, 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 lower the risk of your consuming an infected animals. Although no definitive 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 infective CWD prions and throwing a carcass or carcass parts 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 carcass disposal.
- Don’t use animal attractants such as grain, other animal feed, or mineral attractants 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, and 3) contaminated environments (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 increases 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. These can be found at https://cwd-info.org/recommendations-for-hunters-simple-precautions/.
- If your state wildlife 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.
- Cervid populations, state wildlife agencies, and all those who care about wildlife depend upon what hunters contribute in the battle to manage CWD. By following carcass disposal guidelines, helping to reduce deer numbers in surveillance areas, and submitting harvested deer for testing, hunters help manage the spread of CWD and inform the science needed to develop more effective CWD management practices. Hunters can continue their long history of being conservation advocates by supporting state wildlife agencies in their efforts to establish critically needed regulations and herd management policies. Hunting is critical to the management of CWD, and without the support and participation of hunters, there is little available to wildlife managers to stop the advance of CWD into new herds and new areas.