Wildlife - Deer - Chronic Wasting Disease (CWD)

Chronic Wasting Disease (CWD) is a transmissible or contagious, always fatal, neurological disease that affects members of the Cervidae (deer) Family. Common members of this family include white-tailed deer, elk, mule deer, moose, caribou, red deer, and fallow deer. The only wild free-ranging member of the deer family found in South Carolina is the white-tailed deer. Currently, there is no evidence that CWD can be transmitted to humans or domestic livestock. The disease is not caused by a virus or bacteria, but is rather the result of a naturally occurring protein, called a prion, which 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. Prions associated with the disease are found throughout the body of infected animals, but are found in higher concentrations in the eyes, lymph nodes, and nervous tissues like the brain and spinal cord.

CWD is one of a family of diseases called transmissible spongiform encephalopathies. (TSEs). Other TSEs include mad cow disease or bovine spongiform encephalopathy (BSE) in cattle, scrapie in sheep, feline spongiform encephalopathy in cats, and Creutzfeldt-Jakob disease (CJD) and variant (vCJD) in humans.

Clinical signs appear 1.5 to 3 years after exposure and include excessive salivation and grinding of teeth, increased drinking and urination, dramatic loss of appetite, weight and body condition, poor hair coat, and head tremors. Infected animals develop odd behaviors including decreased interaction with other animals, listlessness, lowering of the head, blank facial expression, walking in circles, staggering, and standing with a wide stance. Prior to the onset of clinical signs, deer infected with CWD can appear normal and healthy. Infected animals are shedding infectious prions during this period before being symptomatic and showing clinical signs.

The only practical method for diagnosing CWD is by testing brain stem tissue or lymph nodes from dead animals. There is no practical live-animal test.

Infected animals shed prions through saliva, feces, blood, and urine. Other animals can become infected through direct contact with an infected animal, ingesting or consuming prions in feces, or bodily fluids and through indirect contact from an infected environment, ingesting prions present in soil contaminated with the feces or bodily fluids of an infected animal. Once the disease occurs in an area, evidence demonstrates eradication is unlikely. The prions that cause CWD persist in the environment and may remain infective for years. High deer densities, as well as, practices like feeding or baiting that unnaturally concentrate deer can facilitate transmission. There is currently no evidence that CWD can be transmitted to livestock or humans.

In 1967, CWD was first recognized in captive mule deer in Colorado. The first documented case of CWD in a free-ranging cervid was discovered in 1981 in a Colorado elk. The disease has since been detected in 35 states including: Alabama, Arkansas, California, Colorado, Florida, Kansas, Kentucky, Louisiana, Idaho, Illinois, Indiana, Iowa, Maryland, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Mexico, New York, North Carolina, North Dakota, Oklahoma, Ohio, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin, Wyoming, and the Canadian provinces of Alberta, Manitoba, Quebec and Saskatchewan. CWD also has been detected in South Korea (captive elk) and Norway (reindeer and moose).

Control is extremely difficult once CWD becomes established in a natural population. 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 diagnosed. Since there is no vaccine or treatment 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 through 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.

To guard against importing CWD from another state, since 2004 South Carolina has regulated the transportation of hunter-harvested cervids (deer, elk and moose) from CWD-infected states.

It is illegal to import into South Carolina or possess in South Carolina a whole cervid carcass or carcass part from an infected state (see list below), except the following may be imported:

Quarters or other portions of meat with no part of the spinal column or head attached; meat that has been boned out; hides with no heads attached; clean (no meat or tissue attached) skulls or skull plates with antlers attached; antlers (detached from the skull plate); clean upper canine teeth from elk, also called “buglers,” “whistlers,” or “ivories;” and finished taxidermy heads.

Hunters traveling elsewhere should check with the wildlife agency in their destination state to determine its CWD status and to determine what restrictions the state may have on the movement of carcasses.

States where CWD has been diagnosed include: Alabama, Arkansas, California, Colorado, Florida, Kansas, Kentucky, Louisiana, Idaho, Illinois, Indiana, Iowa, Maryland, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Mexico, New York, North Carolina, North Dakota, Oklahoma, Ohio, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin, Wyoming, and the Canadian provinces of Alberta, Manitoba, Quebec and Saskatchewan.

Report any illegal cervid importation to Operation Game Thief 1-800-922-5431

As a pro-active precaution to keep Chronic Wasting Disease (CWD) out of South Carolina, a regulation (Reg. 123-54) has been put in place that prohibits the use of many commercially available deer lures.

"No person shall possess or use for the purpose of taking, attracting, or scouting any wild animal in SC any substance or material that contains or purports to contain any excretion collected from a cervid (deer) including urine, feces, blood, gland oil, or other body fluid. This does not prohibit the use of synthetic products or substances collected by a hunter from deer legally harvested in SC."

Prions which are the CWD agent readily bind to soil minerals where they can remain infectious. If cervid urine containing prions is put on the landscape by hunters (e.g., in a scrape or other area used by cervids), prions may bind to soil and contaminate that location for years or decades. Urine sold commercially is collected from captive cervid facilities. Extensive movement of animals between facilities, limited and delayed testing of animals, and shared equipment between herds make captive cervids a high risk for CWD. Nationally, CWD continues to be found in captive cervid facilities, with 40 facilities testing positive since 2012 in 9 states. Urine products are frequently batched/combined from multiple locations and distributed across the country via retail, internet, and catalog sales. Urine production and sales is not regulated by any government agency, nor are there any testing or marking requirements of urine products.

This regulation does not prohibit the sale of these products or the possession of these products in someone's home, business or vehicle. It simply prohibits the use of any product that contains natural deer urine or other body fluid when hunting, scouting or viewing wildlife. For hunters that like to use these products, there are numerous synthetic formulations on the market. This "urine ban" is not unique to South Carolina. Numerous states have implemented similar regulations or legislation and many more are considering it. The deer attractant industry is adjusting accordingly and producing more synthetic products every year. Additionally, hunters in SC are not prohibited from using urine or glands collected from deer legally harvested in SC. While this may be an inconvenience or a change for some hunters, it is a necessary step to take in the fight to keep this disease out of our state.

SCDNR is following the lead of a growing list of states, as well as, recommendations from wildlife disease professionals and the Association of Fish and Wildlife Agencies (AFWA) in prohibiting the use of natural urine-based products.

AFWA represents North America's state, provincial, and territorial fish and wildlife agencies to advance sound, science-based management and conservation of fish and wildlife in the public interest. AFWA has developed Best Management Practices (BMPs) for the Prevention, Surveillance, and Management of Chronic Wasting Disease (CWD) based on the best available peer-reviewed science and field-tested methods. These BMPs represent the contributions of more than 30 wildlife health specialists, veterinarians, and agency leaders actively engaged in CWD issues across North America. The AFWA BMPs recommend prohibiting the use of natural urine-based products.

• AFWA BMPs (includes hundreds of peer-reviewed references)

Opposition to bans of natural urine-based products ignores the large body of accepted scientific evidence and disregards the wellbeing of South Carolina deer. SCDNR utilized the standard annual regulations package, submitted to the South Carolina legislature for approval, for the promulgation of these regulations. This is a process conducted in an open, public forum.

It has been stated that the captive cervid facilities of urine producers are “100% monitored” apparently referring to voluntary participation in the USDA Herd Certification Program (HCP) and other industry-led herd protection efforts. No live animal test for CWD is recognized by the USDA, and the primary tool of the HCP is postmortem testing. This means testing deer that die in a facility. Due to the long incubation period of CWD, deer can shed the disease agent for months or years before appearing sick or dying. Forty captive cervid facilities have tested positive for CWD since 2012 with 40% (16 facilities) enrolled in the USDA Herd Certification Program. This clearly demonstrates the shortcomings of the HCP and emphasizes the fact that captive facilities continue to test positive for CWD, including facilities that have been enrolled in the USDA HCP for years. In fact, CWD has been detected in 21 new captive facilities since January 2018 with 9 (42%) of these facilities being enrolled in the USDA HCP as low risk for CWD.

Enrolling in the USDA HCP program doesn't prevent or eliminate potential previous exposures to CWD that my take years to become apparent. Additional industry programs may be entered by manufacturers, but these use the current USDA HCP as their foundation. They rely on additional “physical inspection” of animals in addition to postmortem testing required by the USDA program. Physical inspections cannot diagnose CWD. Physically inspecting 100 percent of animals in a facility or testing 100 percent of animals that die in a facility does not prevent CWD. Animals can appear normal and be actively shedding the disease agent in body fluids for months to years prior to death. Just like there is no way to put toothpaste back in the tube, there is no way, after the fact, to recall urine products that have since been distributed into the environment by hunters.

Despite what has been stated, urine and urine products are not regulated by USDA even if they come from facilities that are enrolled in the USDA HCP. There is no USDA oversight on how urine is collected, mixed, shipped, bottled, etc. The USDA program is only related to deer at the facilities, not the production of urine or urine products, and no commercially available CWD test for products has been approved by USDA.

"Testing" urine products before sale and distribution is not currently viable. There are many questions and uncertainties including sensitivity of the test, number of replicates required, use of positive controls, scale of testing, response to positive tests, and verification of results. Even in the event of a positive test, it may be difficult to trace the product to a deer or even to a specific farm. If a test of natural urine were to be utilized in the future, there would need to be significant research to properly address the quality control and quality assurance needed to ensure no CWD was present. Any approved test must be conducted by an unbiased third party to ensure validity of the results.

Manufacturers should be commended for recognizing the potential impact of CWD and developing programs to address this issue. However, these programs are currently voluntary and the underlying legal authority in not clear. These programs are simply the industry attempting to police itself. With respect to the wellbeing of deer in South Carolina, the uncertainty of the industry is expressed in that it can only limit or reduce the potential of CWD being present in their herds or that their products may contribute to the spread of CWD. While we appreciate their efforts, we cannot accept any unnecessary risk regardless of how much it is reduced.

This issue boils down to a few simple questions:

1. Can prions, the CWD agent, be shed in urine? Yes.
2. Can prions contaminate the environment? Yes.
3. Can deer be infected with CWD from prions in the environment? Yes.
4. Can the industry guarantee there are no prions in the urine/body fluids they sell? No.
5. Given the fact that CWD is impossible to eliminate from a wild population, are the benefits of allowing urine-based products greater than the risk of allowing a practice that could expose the state’s deer herd to a fatal, contagious disease? No.

The use of natural urine-based products is a low risk, but not a zero risk. To be effective stewards of the deer resource it is important that SCDNR do all it can to prevent CWD. Just like carcass importation regulations that are now in place in virtually all states, prohibiting the use of natural urine-based products is a recommended preventative measure based on the current knowledge of CWD. For hunters that wish to use scent products, they can utilize synthetic products as well as urine and glandular secretions from deer legally harvested in South Carolina. Should future research reveal that urine is definitively not associated with CWD transmission or provides an effective method to test urine products that is credibly verified and regulated, then SCDNR regulations can be amended to be more flexible. Until that time, no controllable risk is acceptable.

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, the current recommendation from the World Health Organization (WHO) and the Centers for Disease Control (CDC) is that humans should not consume meat from known infected animals.

SCDNR maintains its ban on the importation of live deer and elk into South Carolina. It is well documented that the movement of infected, live cervids by humans has resulted in broad geographic leaps in the nationwide distribution of CWD. Thanks to efforts by SCDNR and the state legislature, South Carolina has historically been a closed-door state and not allowed importation of cervids from other localities. This is an important point, because states vary with respect to allowing cervids to be transported for commercial purposes.

SCDNR has been criticized in the past for not being more liberal in supporting or allowing deer farming or high fenced “shooter buck” operations that depend on moving animals into the state. However, since CWD has become a concern, a growing list of states have discontinued allowing deer to be imported for any purpose.

Report any illegal cervid importation to Operation Game Thief 1-800-922-5431

Yes, SCDNR has a cooperative agreement with the Southeastern Cooperative Wildlife Disease Study (SCWDS) related to wildlife disease expertise and diagnostics. CWD surveillance in South Carolina began in 1998 when SCWDS began testing for the disease in clinical cases that it received from all cooperating states. With the availability of federal funding in 2003 SCDNR began active surveillance of otherwise healthy hunter killed deer. This continued until 2012 at which time federal funding for CWD surveillance was eliminated. During this period of active surveillance over 4,000 deer were tested via statistically based sampling in all counties.

Since 2012 targeted surveillance of clinical animals that fit the disease profile has continued. Beginning in 2023 active surveillance was resumed with SCDNR contracting with numerous taxidermists around the state to collect samples for testing based on a risk assessment disease model created by the Cornell Wildlife Health Lab.

Approximately 6,000 deer have been tested for CWD through all years. CWD surveillance will continue with a combination of surveillance on hunter harvested deer of healthy appearance and of clinical suspect animals with symptoms consistent with CWD. In addition, any illegally possessed or imported deer and other high-risk animals will be euthanized and tested for CWD.

The detection of CWD in South Carolina would have significant biological, ecological, economic and sociological implications. CWD would represent a serious long-term threat to the health of white-tailed deer in the state. Keeping SC CWD free will require vigilant effort not only from the SCDNR but from hunters and landowners as well.

• Hunters, landowners and members of the public can report sick or abnormally thin deer or deer dead of unknown causes to their local Wildlife Biologist or SCDNR Wildlife Section office at (803) 734-3886.
• Know and follow regulations when hunting out-of-state. It’s illegal to bring into South Carolina carcasses of deer, elk, moose, caribou and other members of the deer family from states and provinces where CWD has been detected.
• Know and follow regulations related to the use of natural urine or gland based scents, lures and attractants. It is illegal to possess or use any substance or material that contains or purports to contain any excretion collected from a cervid (deer) including urine, feces, blood, gland oil, or other body fluid for the purpose of taking, attracting, or scouting any wild animal in SC.
• Report any illegal cervid importation to Operation Game Thief 1-800-922-5431
• Get the facts and learn as much as you can about the disease from reliable sources and then help spread the word to your friends, family and hunters you know.

Each year numerous South Carolina residents go deer or elk hunting in states listed above that have CWD. As noted previously, the Department requires that any South Carolina hunter hunting in a state or province where CWD has been identified follow the carcass importation regulations.

Many of these states have mandatory or voluntary CWD testing programs. If you have your deer tested for CWD and are notified by mail, e-mail, or telephone that the CWD test was positive and you have brought any part of the carcass back to South Carolina, please contact the Department at 1-803-734-8738.

Even though CWD has not been detected in South Carolina there are some simple precautions that all hunters should take:

• Do not shoot, handle, or consume any animal that is abnormal or appears to be sick. If you see a sick deer, please contact the Department immediately.
• Wear latex or rubber gloves when field dressing your deer carcass (this precaution applies to dressing any game).
• Bone out meat from your animal. Do not saw through bone and avoid cutting through the brain or spinal cord (backbone).
• Minimize the handling of brain and spinal tissues or fluids.
• Wash hands and instruments thoroughly after dressing or processing is completed.
• Avoid consuming brain, spinal cord, eyes, spleen, tonsils, and lymph nodes of deer. Normal field dressing coupled with boning out a carcass will remove most, if not all, of these body parts.
• If you have your deer commercially processed, request that your animal be processed individually, without meat from other animals being added.