What is Chronic Wasting Disease (CWD)?
Currently, this disease CWD is known to affect the nervous system in white-tailed deer, mule deer, red deer, elk, and moose, which are all members of the family Cervidae. Chronic Wasting Disease is one in a group of diseases called the transmissible spongiform encephalopathies (TSEs), such as scrapie in domestic sheep and goats, and bovine spongiform encephalopathy (BSE) in cattle. CWD cannot be transmitted to humans or livestock. It is caused by prions, a type of misfolded protein that causes host animal to replicate the misfolded protein. Prions interrupt and degrade nerve cells, ultimately eliminating basic nervous system functions, which leads to death.
What are the symptoms?
Symptoms appear late in the disease, from 16–36 months after infection. These include:
- Emaciation or generally poor body condition,
- Decreased activity and/or erratic behavior,
- Wide, low stances and blank expressions,
- Excessive drinking and urination,
- Salivation and grinding of teeth,
- Keeping distance apart from herd, and
- Loss of fear of humans
How is it spread?
Chronic Wasting Disease is spread among individuals by indirect and direct contact with saliva, urine, feces, or a carcass. These sources carry prions, which are deposited on the ground and in the soil, and can be picked up by other animals during foraging activities. Research indicates that some plants bind prions during growth, and that antler rubs may spread prions. Thus, reservoirs of prions in the environment enable transmission. While mother-offspring transmission is possible, lateral transmission between two animals is the typical route of infection.
Can it affect livestock or humans?
No. Although it never hurts to be cautious, there is no indication that CWD can be transmitted to domestic livestock or humans. While some exotic, cervid livestock (i.e., red deer) can be infected with CWD, traditional livestock (cattle, sheep, goats, etc.) cannot.
Nevertheless, experts advise hunters to harvest only healthy looking animals. Sickly looking animals should be assessed for diseases and not included in one’s diet. The brain, eyes, tonsils, spine, spleen, and lymph nodes, should not be consumed, as these are where prions accumulate in high density. Contact with these parts should be avoided. Handle carcasses in a way that they are boned out to remove all nervous system tissue in areas with CWD. Be sure not to cut meat with saws or knives used to cut bone, and dispose of the carcass by burying it at least 6 feet deep or in an approved landfill to prevent exposure to other cervids in the area.
What should I do if I see an animal that might have CWD?
- Do not attempt to touch, kill, or move the animal in any way.
- Carefully document the location of the animal, and any pertinent details.
- Contact the nearest Texas Parks and Wildlife Game Warden or Wildlife Biologist or the Texas Animal Health Commission, if it is a captive cervid, immediately.
- If directed to send a sample for testing by TPWD or TAHC, contact your local veterinarian for advice and professional assistance in collecting the sample.
- Follow any instructions given by those agencies for follow-up.
Continue to be vigilant for future cases of potentially infected cervids.
What are the recommended treatment and prevention strategies for CWD?
There is no vaccine to prevent infection, and once infected, there are no effective treatments to cure infected animals. Although researchers continue to work to develop such tools, we must work to prevent the spread of CWD through management of cervid populations. There are a number of ways to minimize the transmission of CWD, but the easiest solutions are to (1) removing potentially infected animals, (2) preventing high cervid densities by continuing to hunt and harvest and (3) minimizing places where cervids congregate, such as feeding stations.
How can I help?
The best way to help is to remain vigilant and carefully follow any requests or regulations from Texas Parks and Wildlife or the Texas Animal Health Commission. Early prevention provides the best chance to minimizing the spread of the disease. Encourage your fellow Texans to remain clam in the face of this situation, and work to prevent the spread of misinformation. Look to the resources below for more detailed, factual information on CWD.