Tennessee Wildlife Federation is committed to keeping Tennessee CWD free.
As such, we are working with the Chronic Wasting Disease Alliance and field experts to learn more about the disease. Recently, the Federation hosted a tele-townhall discussion with Dr. John Fischer to discuss current trends and concerns regarding chronic wasting disease. He is the director of the Southeastern Cooperative Disease Study at the University of Georgia College of Veterinary Medicine.
Chronic wasting disease (CWD) is a highly-contagious neurological disease affecting deer, elk, and other cervids. Like mad cow disease, it’s caused by a misfolded protein called a prion. It leads to brain degeneration, extreme weight loss, abnormal behavior, and then death. There’s no known cure and it can survive in the soil for years—even decades.
As Dr. Fischer describes it: “This is the disease agent from outer space. It is built to last.”
According to the CWD Alliance, CWD has been confirmed in 23 states, including Tennessee’s neighbors Arkansas, Missouri, and Virginia. If it comes to Tennessee, it is a major threat to the state’s deer population along with the food, traditions, and conservation funding it provides.
It is critical that Tennesseans do their part to prevent the spread of the disease to our state.
“Our model is that prevention is the only truly effective method. Once a disease is introduced, it is almost impossible—if not impossible—to eradicate it in a population. Prevention is what we are talking about here, and it is something we firmly believe in in the wildlife disease study,” said Dr. Fischer.
Methods of prevention range from conservative to extreme approaches and are largely regulated by state wildlife management agencies, such as our friends at Tennessee Wildlife Resources Agency.
During the call, Dr. Fischer discussed various practices that may lower the risk of CWD transmission. Those include:
Avoiding importation or transportation of live animals, whether captive or wild being moved for restoration and relocation programs. “By far, the riskiest practice is the importation of live animals,” said Dr. Fischer.
Avoid movement of dead animals, including tissue. Because prions—the disease agent—is present in the nervous system, lymphoid, and muscle tissue, it is possible to expose unaffected areas to the disease by importing whole carcasses and even tissues. **Note that as of 2017, TWRA has a ban on the importation of carcasses from 24 states. Always check and follow current regulations set by the state agency.
Properly dispose of any tissues brought into the state. Dr. Fischer recommends working with the state wildlife management agency (TWRA) to ensure proper disposal of any imported tissues. For most, this may mean controlled landfill disposal.
Avoid use of urine products and baiting/feeding stations. While Dr. Fischer acknowledges that the level of risk of CWD from these products is not known, the prion that causes infection is present. More significant is the “risk of animals congregating artificially and increasing the risk of transmission. It’s like a deer daycare center where critters can gather and share germs,” noted Dr. Fischer.
Use locally sourced hay, wheat, and plant products, where possible. “Prions do bind superficially in labs, but this has not been tested in the field,” said Dr. Fischer. In other words, it is possible that prions are transmitted by plant and plant-product movement.
In addition to prevention, Dr. Fischer discussed the gravity of the disease. Even in captive herds that have been tested by the USDA and other regulatory agencies, animals have later tested CWD positive. Researchers have not been able to determine how these animals were exposed or infected—or perhaps why CWD did not show up on previous tests.
There is growing concern about the contamination of venison and its effects on humans if consumed. A similar condition called Creutzfeldt-Jakob disease affects humans, which means it’s a possibility that CWD could cross the species barrier. A study by the Canadian Food Inspection Agency and the University of Calgary showed that macaques—a type of primate—that were fed infected meat or injected with CWD developed the disease. However, these results are preliminary and haven’t been reproduced.
It is important to note that there is no current evidence that shows CWD can or has infected a human.
Finally, Dr. Fischer discussed how hunters can prevent the transmission of the disease. Currently, the onus is on the hunter to test harvested deer for CWD and properly dispose of carcasses. And, if testing for CWD is requested, results return to the hunter, not the state regulatory agency, further complicating disposal and reporting of the disease. Fischer encouraged hunters to “practice prevention above and beyond the call of duty” to limit transmission of CWD.
When field dressing an animal or disposing of tissue, Dr. Fischer recommends hunters reference state and Centers for Disease Control regulations and recommendations.
“We have to have the support of the public in order to reduce CWD-associated risks, especially when we look at preventing introduction into a new state or area within a state,” said Fischer.
Tennessee — it is your responsibility to stay CWD free.
Interview with Dr. Fischer
2: Using Urine Attractants
3: Archery Trade Association Deer Protection Program
4: Keep Tennessee CWD Free and Mitigating Risk Factors