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Chronic Wasting Disease (CWD)

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What is CWD?

Chronic wasting disease (CWD) is a progressive, fatal disease of the nervous system of white-tailed deer, mule deer, elk and moose. It belongs to a family of diseases known as Transmissible Spongiform Encephalopathies (TSEs) or prion diseases. Although CWD shares certain features with other TSEs, like bovine spongiform encephalopathy (or mad cow disease), scrapie in sheep and goats, and Creutzfeldt -Jakob disease in humans, it is a distinct disease affecting only deer, elk and moose. It causes damage to portions of the brain; creating holes in the brain cells and causing a sponge-like appearance.

CWD is transmitted both directly through animal-to-animal contact and indirectly through food and soil contaminated with bodily excretions including feces, urine and saliva. Contaminated carcasses or high-risk carcass parts may also spread the disease indirectly through environmental contamination, which lasts for years, if not decades.

CWD is a slowly progressing disease and is harbored in an infected animal long before the animal shows signs.  Signs typically are not seen until the animal is 12-18 months old and may take as long as 3 years or more. CWD attacks the brains of infected animals, causing them to become emaciated, display abnormal behavior, lose bodily functions, become weak and eventually die. Signs include excessive salivation, loss of appetite, weight loss, excessive thirst and urination, listlessness, teeth grinding, lowering of the head and drooping ears.

Currently, there is no direct evidence that CWD poses a risk to people; but, the Centers for Disease Control (CDC) recommends to have deer meat harvested in a CWD positive area tested for CWD and that meat from an animal that tests positive for CWD should not be consumed.

Please understand that CWD poses the largest threat to Tennessee’s deer and elk populations since the dawn of wildlife management more than 100 years ago.

Public Health Concerns

The Centers for Disease Control and Prevention (CDC) is the nation’s health protection agency and is the authority on disease threats to humans, including the impacts of chronic wasting disease.  See the CDC website for more details on CWD Prevention

A summary of CDC Recommendations: To date, there have been no reported cases of CWD infection in humans. However, some animal studies suggest CWD poses a risk to certain types of non-human primates.  To be as safe as possible and decrease the potential risk of exposure to CWD, hunters should take the following steps when hunting in areas with CWD:

  • Have your deer tested for CWD before eating it.  If it tests positive, do not eat the deer.
  • When field-dressing or processing a deer:
    • Wear latex or rubber gloves
    • Minimize how much you handle the organs, particularly the brain or spinal cord tissues.
    • Do not use household knives or other kitchen utensils
  • If you have your deer or elk commercially processed, consider asking that your animal be processed individually to avoid mixing meat from multiple animals.
U.S. Geological Survey -  CWD Positive Map

Distribution of CWD

Chronic wasting disease (CWD) has been detected in 26 US states, three Canadian provinces, Norway, Finland, Sweden and South Korea in free-ranging cervids and/or commercial captive cervid facilities.  Members of the cervid family in North America include white-tailed deer, mule deer, elk, and moose. 

For the most up to date distribution information see the U.S. Geological Survey (USGS) webpage.

CWD Fact Sheets

You can save, print, and study these helpful documents on CWD.

TWRA documents: How Can I Help with CWD? And Why Shoot More Deer in Unit CWD?

University of Tennessee Extension Document on CWD: https://extension.tennessee.edu/publications/Documents/W832.pdf

USGS Document on CWD: https://pubs.usgs.gov/of/2017/1138/ofr20171138.pdf

CWD Videos 

CWD Classroom. Chuck Yoest, TWRA’s CWD Coordinator, and Wildlife Health Specialist with UT Extension and TWRA Veterinarian, Dr. Dan Grove,  give a thorough review of all things CWD.


Public meeting in Fayette County, on April 9, 2019 talking about what CWD is, how we found it, why it matters, and what we are doing.                                       


Executive Director of TWRA, Ed Carter speaks about TWRA’s actions regarding the recent discovery of CWD in Tennessee.                                                      


Review the new 2019-2020 deer hunting season regulations for Unit CWD.                                                                                                                                                                                                     



Hunting with CWD Videos

Wildlife officer Eric Anderson and taxidermist Chris Butt discuss what needs to be done to legally bring a deer harvest from another state back into TN.”                         

How to skin and debone a deer.

                                                                                                         

Chris Butt with Wildlife Taxidermy walks us through the process of caping your animal out in order to comply with Tennessee's import restrictions for bringing harvested deer into the state

Educational Links

Our Friends At TN Wildlife Federation Understand The Impact Of CWD

The state’s largest sportsman’s group is the Tennessee Wildlife Federation. This is an organization that TWRA has worked with on numerous projects through many years.  Like our agency, the TWF is extremely concerned about Chronic Wasting Disease. Please visit TWF’s page about CWD to learn more from the sportsman’s point of view concerning the perils of this deadly disease.

Trustworthy sites to learn more about CWD

Chronic Wasting Disease Alliance

10 Reasons You Don't Want CWD