Chronic Wasting Disease

Chronic Wasting Disease

Chronic Wasting Disease (CWD) is a major threat to the nation’s deer and elk populations and the conservation funding generated by big game hunting.

CWD is in four states bordering Tennessee. If it comes here, it will decimate the state’s deer herds and forever impact Tennessee’s outdoor traditions and conservation funding. Outdoorsmen must do their part to shield the herd from the disease while advocating for policies to combat its spread.

Join with other Tennessee outdoorsmen and women to pledge to Keep Tennessee CWD Free. Only vigilance and proper management of the herd will protect Tennessee from CWD.

Keep Tennessee CWD Free

Chronic Wasting Disease (CWD) is a highly-contagious neurological disease that infects deer, elk, and other cervids. It is similar to mad cow disease and Creutzfeldt-Jakob disease (humans). CWD causes wasting, including brain degeneration, extreme weight loss, abnormal behavior, and death. Infected animals may appear to have no symptoms for years while transmitting the disease and are often killed by predators, vehicles, or other diseases before symptoms show. There is no known cure.

The disease is caused by a misfolded protein called a prion, which is nearly impossible to destroy and remains in the environment indefinitely. The prion is transmitted to new animals through direct animal-to-animal contact, and contact with feces, saliva, carcass parts, as well as contaminated environments, such as soil. Once CWD is introduced in the state, it is unlikely to be contained.

Now with CWD confirmed in 25 states, including our neighbors Arkansas, Mississippi, Missouri, and Virginia (Source: CWD Alliance), it is more important than ever for Tennessee outdoorsmen to be vigilant.

CWD will decimate Tennessee deer herds and change the face of conservation in Tennessee. Currently, hunters and anglers are the single largest source of funds for wildlife management in the state. As CWD affects herds and reduces hunting opportunities, fewer licenses and supplies will be sold, greatly decreasing conservation funds generated from those purchases. As hunter numbers decline, time-honored traditions will disappear from Tennessee’s landscapes and we’ll lose the original advocates for sound conservation policy in the state.

State, regional, and national efforts are underway to expand research of the disease and to strengthen containment efforts. Tennessee Wildlife Federation will continue to be the voice for sportsmen and women, and all those concerned about wildlife conservation in Tennessee. Today, the most important step individuals can take is to educate themselves about how they can make sure they don’t accidentally spread the disease. Pledge now to do your part to keep Tennessee CWD free.

In the News

Quick Facts

  • The disease is 100% fatal and has no cure.
  • An infected deer can be infected for months to years with no outward signs.
  • Deer in 25 states have tested positive for CWD. Those states include Tennessee neighbors Arkansas, Mississippi, Missouri, and Virginia.
  • CWD is caused by an easily transmitted prion—a misfolded protein that is neither a virus nor a bacterium.
  • The prion is extremely difficult to destroy. It can remain infectious in the environment, such as in the soil, indefinitely.
  • There is no practical way to test live wildlife for CWD. Hunters can submit tissue samples for testing.
  • Once CWD is introduced to an area, it is highly unlikely it can be controlled. Prevention of disease transmission is the best method of keeping Tennessee CWD free.
  • A University of Tennessee study estimates that if CWD is found in Tennessee, the state will lose $98 million in economic activity and 1,400+ jobs.

More from the Federation about CWD

Frequently Asked Questions

What is Chronic Wasting Disease?

Chronic Wasting Disease (CWD) is a highly-contagious neurological disease that infects deer, elk, and other cervids. It is similar to mad cow disease, scrapie that infects sheep, and Creutzfeldt-Jakob disease that affects humans. There is no known cure.

CWD causes the brain to degenerate, extreme weight loss, abnormal behavior, and then death. Infected animals can show no symptoms for years while still transmitting the disease throughout the herd.

The disease is caused by a misfolded protein called a prion that continues to multiply in the infected animal. Prions infect new animals through direct animal-to-animal contact, contact with feces, saliva, and carcass parts, as well as through environments (soil, etc.) contaminated with any of the above.

Additionally, it is important to note that prions are neither a virus or bacterium and are extremely difficult to destroy. In fact, once they get into the environment they can remain stable and infectious. Many in the wildlife science community believe that once they are established in an area, it is not realistic to ever remove them from the wild environment.

Can CWD be transmitted to humans?

While there have been no known cases of transmission to humans at this time, recent research has produced conflicting results about transmission to primates. A 13-year-long study by the National Institutes of Health showed no trace of CWD within primates after they were exposed to the prion, including through food. A 3-year Canadian study showed CWD crossing the species barrier to infect primates. However, the Canadian results are preliminary and have not been published, so its methodology and accuracy have not been assessed by the scientific community.

It is recommended that venison from a CWD-positive deer, or any deer showing signs of illness, be disposed of—not consumed.

Sending a sample to be tested in a lab is the best way to determine if a deer is infected. You will likely never see an animal showing symptoms of CWD. Symptoms only appear long after infection and the unhealthy animal is often first killed by predators, vehicles, or other diseases.

This could eliminate an important source of food for many Tennesseans, while also removing an incentive to get out and hunt. The U.S. Centers for Disease Control and Prevention issued this article about the potential of transmission of CWD to humans.

Is Chronic Wasting Disease the same as Epizootic Hemorrhagic Disease (EHD) or Bluetongue?

No. Chronic Wasting Disease is a contagious disease with no known cure that has the potential to decimate wild deer populations.

Epizootic hemorrhagic disease (EHD) and bluetongue, while both contagious, are two separate types of viral hemorrhagic disease that can cause short-term declines in localized cervid populations, but do not seem to have any significant effect on long-term herd health and survival.

Both EHD and bluetongue do cause a significant reduction in the physical health and appearance of deer (i.e., wasting) and ulceration, particularly of the mouth and tongue.

Because the viruses are transmitted by biting insects, such as midges, the disease comes and goes with the seasons. Additionally, some deer do survive EHD and bluetongue and are able to pass along immunity to their offspring. This is not the case with CWD as it is always fatal.

What does deer farming have to do with Chronic Wasting Disease?

Deer farming creates high-density populations of deer, making it an ideal environment for transmitting CWD. While deer farms are fenced, escapes of captive deer and elk occur when fences are damaged by storms. Deer farms also regularly transport deer across state lines, which appears to serve as a method by which CWD can be established in other captive and potentially wild deer herds. In Tennessee, it is illegal to farm native deer species, with the exception of elk, which may be farmed under certain circumstances.

For these reasons, among others, the Federation opposes deer farming in our state.

Is controlling CWD an option?

In short, no. Preventing CWD from entering an area is really the only effective means of controlling the disease. The prion is extremely resistant to control mechanisms and, to date, no method has successfully destroyed the prion and eradicated the disease from infected areas.

Further, once CWD is introduced to an area, attempts to contain the disease—including monitoring herds, testing deer, culling herds, containing infected populations, and enforcing strict carcass disposal and importation rules—are both extremely costly and controversial.

How much could CWD affect Tennessee’s herd?

In Wyoming, wildlife biologists estimate a 10 to 20 percent decrease in its mule deer population each year because of CWD. In parts of southern Wisconsin, the infection rate has been measured between 30 to 50 percent of the deer sampled, with bucks seemingly more susceptible to CWD than does. Because CWD is always fatal, we know that parts of Wisconsin will lose at least half of its deer herd.

This means if the disease is ever established in Tennessee, it is not unreasonable to say that it could greatly reduce hunting opportunities and the chance for new hunters to carry forward an important piece of American culture.

What can I do to Keep Tennessee CWD Free?

There are several measures Tennesseans can take to keep Tennessee CWD free.

First and foremost, Tennessee law prevents importation, transportation, or possession of deer or other cervid carcasses from outside the state. More information about this restriction and processing requirements is available here at www.tn.gov/twra/hunting/cwd.html

Additionally, Tennesseans can minimize the risk of CWD by taking these simple precautions.

  • Do not transport animals or carcasses. Before bringing an animal product into Tennessee, it must meet minimum processing standards. Always consult current Tennessee Wildlife Resources Agency guidelines.
  • Follow recommendations for disposal of the carcass and tissues of infected animals.
  • Field dress and bury the offal and tissues of harvested animals. Or, field dress and double bag the offal and tissue for disposal in a landfill. Use rubber or latex gloves.
  • Do not bait or feed game. In Tennessee, baiting game is illegal. The risk of CWD makes it even more important to avoid this practice. Baiting game attracts deer, thereby artificially increasing the deer population in a small area, increasing opportunities for the disease to be transmitted.
  • Avoid use of urine products. While it is not a known pathway for infection, urine has been shown to contain the prion that causes CWD. Additionally, it can also attract more animals to a smaller space, increasing opportunities for infection.
  • Report to TWRA any animal that appears to be acting abnormally or appears to be sick. If you harvest an animal that you suspect may be ill, request testing and share results with TWRA.

It is imperative to follow all regulations, restrictions, and recommendations issued by regulatory agencies, such as TWRA and the Centers for Disease Control.

For more information about CWD prevention, listen to this audio recording and visit cwd-info.org

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Photos by Dr. Terry Kreeger