Tennessee wildlife biologists are on the lookout for a disease that could do widespread harm to whitetail deer populations. Fortunately, so far, there's no sign of Chronic Wasting Disease (CWD) in Tennessee.

Ben Layton, a biologist for TWRA's Region III, says, "Tennessee is concerned about CWD and we have been for several years. We have been sending any suspect deer to the Southeast Disease Study Unit in Athens, Ga. for testing."

There is increased concern in many states after three whitetail deer in Wisconsin tested positive for CWD last Fall. That was the first time CWD was detected in a wild whitetail population. Wisconsin will be killing dozens of whitetails this Spring in a special effort to see if any other cases are found.

CWD is a fatal disease of the central nervous system. There is no evidence at this point that it can be passed to humans. In animals however, including whitetail deer, black tail deer, mule deer, and elk, it attacks the brain and spinal cord. There is no treatment, vaccine, or live test for CWD.

It's been found most often in western states, but there is some concern that it could spread east, especially after the most recent cases were found in Wisconsin.

Larry Marcum, TWRA's Chief of Wildlife Management says, "Its possible affect on native deer is tremendous if it were to come into Tennessee. The Tennessee Department of Agriculture oversees the importation of captive deer and elk. They are strengthening their rules. USDA is doing the same. White-tailed deer cannot be imported so we may have a plus from that standpoint."

Of course TWRA recently embarked on an aggressive elk restoration project. Imported animals are often CWD carriers in some states but Marcum said, "we have taken extreme precautions when importing elk to avoid all the areas where CWD occurs or is likely to occur. In fact, we have imported only from Elk Island National Park in Canada which is a closed herd with an extensive history of testing. It is our highest guarantee of CWD free animals."

Layton said only a few whitetails from Tennessee have been tested for CWD to date. "Thus far I believe that Tennessee has only sent 3-4 deer (for testing). Of course all of these have been negative. Tennessee and probably other states will begin more intensive monitoring in the future. We have no definite procedures yet but I expect we will shortly."

Steve Williams, the Director of the U.S. Fish and Wilflife Service said, "the risk, if it occurs in an area is very high. How far it will spread in the country... I think that's unknown at this point."

In places where outbreaks of CWD have occured, thousands of deer and elk
have been destroyed to stop the disease from spreading.

In Texas, an organization called Operation Game Thief is offering a $10,000 reward for information about
anyone trying to illegally import deer into the state.

Here are some Frequently Asked Questions about CWD from the Wisconsin Dept. of Agriculture:

What is chronic wasting disease?
Chronic wasting disease (CWD) is a fatal disease of the central nervous system in cervids, a group of animals that includes whitetail deer, black tail deer, mule deer, and elk. It affects the brain and spinal cord. There is no treatment, vaccine, or live test for CWD.

How is it related to mad cow disease?
Both are in a family of diseases called transmissible spongiform encephalopathies (TSE). Mad cow disease is the common name for bovine spongiform encephalopathy or BSE, which affects cattle. Other TSEs in animals are scrapie in sheep, transmissible mink encephalopathy, and feline spongiform encephalopathy in cats.

There are several human TSEs: classic Creutzfeldt-Jakob disease, new variant Creutzfeldt-Jakob disease, fatal familial insomnia, Gertstmass-Straussler-Scheinker disease, and kuru.

TSEs are separate diseases with similar symptoms, which arise from different sources and are transmitted differently. BSE may be the exception - scientists believe it may have infected cattle when they ate feed containing parts from scrapie-infected sheep. New variant Creutzfeldt-Jakob disease in humans has been linked to eating BSE-infected meat.

Is CWD a human health threat?
There is no scientific evidence that CWD affects humans. It has not been associated with eating infected animals. In 16 years of surveillance in infected areas of the western United States, there has been no evidence of the disease affecting any species other than deer and elk.

What causes CWD?
Like other TSEs, chronic wasting disease is apparently caused by an abnormal prion, a type of protein, that replicates itself in the animal’s brain and spinal cord. It causes sponge-like lesions in the animal’s brain.

How is CWD transmitted?
Scientists are not certain, but believe CWD passes from animal to animal in close contact, and perhaps from mother to offspring. The infected animals have eaten a wide range of feeds, and the wild animals had no feed with animal parts in it. Therefore, CWD has not been associated with any particular feeding practice, as BSE has.

What are the symptoms of CWD?
The disease progresses slowly, so animals may be infected and not show any signs for several years. Symptoms include lack of coordination, separation from other animals in the herd, excessive salivation, depression, unusual behavior, paralysis, weight loss, difficulty swallowing, increased thirst and urination, and pneumonia. Signs usually last weeks to months before the animal dies. Most animals are 15 to 35 months old when signs appear, but they may be as old as 13 years.

How is CWD diagnosed?
The only sure way to diagnose CWD is to examine the animal’s brain for the characteristic lesions that make the brain look like a sponge. There is no approved test for live animals, although one is in development.

Where has CWD been found?
CWD was first seen in Colorado deer belonging to several research facilities in 1967. Since then, it has been found in wild deer and elk herds in the area where Wyoming, Nebraska and Colorado meet. It has been found in captive elk herds in Colorado, Nebraska, Montana, Oklahoma, South Dakota, and Saskatchewan, Canada.

Is CWD an animal health threat?
The greatest threat in Wisconsin is probably to Wisconsin’s wild whitetail deer population, because testing and tracing are difficult in wild animals. Wisconsin also has 575 farms with captive whitetail deer, and 272 with captive elk. We have about 100 farms raising red deer, reindeer, fallow deer and sika deer. We don’t know if these species are susceptible to CWD.

There is no evidence that species other than deer and elk are susceptible to CWD.

What are we doing to prevent the spread of CWD in Wisconsin?
We have a voluntary surveillance program for non-whitetail deer and elk farmers. Participants agree to test all animals that die for CWD. If all results are negative (as all have been to date), their herds are certified CWD-free from the date of their enrollment in the program. This makes shipping animals to other states easier.

The Department of Natural Resources has collected samples for testing at deer registration stations during the gun deer season since 1999.

In 2000, Wisconsin ranked fourth in the nation in the number of samples submitted for CWD testing to the National Veterinary Services Laboratory in Ames, Iowa, and in 2001, we ranked sixth. Four of the 5 states ranked higher have mandatory testing.

The DNR registers whitetail farms and the Department of Agriculture, Trade and Consumer Protection registers elk farms and those raising non-native deer species. This makes tracking animals for disease purposes easier and enforcing rules easier. Among those rules is a requirement that deer and elk farms must have fencing that is high enough to keep wild and captive populations from mingling.

The U.S. Department of Agriculture is developing a program to eradicate the disease.

What can elk and deer farmers do?
Captive deer and elk herds are required to be fenced according to standards set in our rules. In addition, we recommend that these herds be surrounded by a second fence. The outer fence should be at least 10 feet away from the inner one. We also strongly urge deer and elk farmers to enroll in the voluntary surveillance program.