What is Chronic Wasting Disease (CWD)?
CWD is an untreatable, fatal neurological (brain and nervous system)
disease found in deer and elk in certain geographical locations in North America. The disease belongs to a family of diseases known as
transmissible spongiform encephalopathies (TSE) or prion diseases. The disease attacks the brain and neural tissue of infected deer
and elk. While CWD is similar to mad-cow disease in cattle and
scrapie in sheep, there is no known relationship between CWD and any other TSE of animals or people.
How is it spread?
It is not known exactly how CWD is spread. It is believed that the
agent responsible for the disease may be spread both directly (animal to animal contact) and indirectly (soil or other surface to animal).
It is thought that the most common mode of transmission from an infected animal is via saliva, feces, and urine.
Where has it been found?
CWD is known to infect free-ranging deer and elk in northeastern
Colorado and free-ranging deer in western Colorado, southern Wyoming,
western Nebraska, South Dakota, Wisconsin, New Mexico and Saskatchewan. It has been diagnosed in elk in game ranches in Colorado, Nebraska, South Dakota, Montana, Oklahoma, Kansas, Alberta and Saskatchewan.
Is it dangerous to humans?
Epidemiologists with the federal Centers for Disease Control and Prevention in Atlanta and epidemiologists at the Colorado Department of Public Health and Environment have studied chronic wasting disease and found no evidence that CWD poses a risk to humans or domestic animals.(Over 16 years of monitoring in the infected area in Colorado has found no disease in people or cattle living there.) The World Health Organization has likewise said there is no scientific evidence CWD can infect humans. However, as a precaution the WHO also says no part of a deer or elk with evidence of CWD should be consumed by people or other animals.
What Precautions should hunters take?
Health officials advise hunters not to consume meat from animals known to be infected with the disease. Boning out meat is recommended. In addition, they suggest hunters take simple precautions such as wearing latex gloves when field dressing carcasses, minimize handling of brain and spinal tissues, wash hands and instruments thoroughly after field dressing is completed, avoid consuming brain, spinal cord, eyes, spleen, tonsils, and lymph nodes of harvested animals, and finally request that your animal is processed individually, without meat from other animals being added to meat from your animal.
How can you tell if a deer has CWD?
Because the brain is the organ affected by the disease, infected animals begin to lose bodily functions and display abnormal behavior
such as staggering or standing with very poor posture. Animals may
have an exaggerated wide posture, or may carry the head and ears
lowered. Infected animals become very emaciated (thus "wasting" disease) and will appear in very poor body condition. Infected animals will also often stand near water and will consume large amounts of water. Drooling or excessive
salivation may be apparent.
What should I do if I see a deer that shows CWD symptoms?
Accurately document the location of the animal and immediately contact
the nearest Wildlife Division or Law Enforcement Division office of the Texas Parks and Wildlife Department or call TPWD headquarters in
Austin toll-free at
and enter 5 for wildlife and 1 for general wildlife information.
Or contact, the Texas Animal Health Commission toll-free at
Do not attempt to touch, disturb, kill, or remove the animal.
Can I have deer venison tested?
Deer "venison" cannot be tested-only brain and neural and lymph node
tissue can be tested to detect the presence of CWD. There is no
means of testing deer tissue samples for CWD in Texas at present. However, the Texas Veterinary Medical Diagnostic Lab in College Station is in the process of being certified by the U.S. Department of Agriculture to be able to test CWD samples. Eventually, the public may be instructed to contact the Texas Animal Health Commission for information on testing.
Is the meat safe to eat?
While the agent that produces chronic wasting disease in deer and elk
has not been positively identified, there is strong evidence to
suggest that abnormally shaped proteins called prions are involved.
Research completed to date indicates that the prions accumulate only in certain parts of infected animals-the brain, eyes, spinal cord, lymph nodes, tonsils, and spleen. Based on these findings, hunters are recommended to bone out their meat and consume only muscle tissue from harvested animals.
What is being done to combat CWD?
Texas officials have restricted importation of live deer and elk into
the state. The Texas Parks and Wildlife Department and the Texas Animal Health Commission are also working with deer and elk breeders to set up a voluntary CWD monitoring program. This fall, TPWD will
begin testing hunter-killed deer and other suspect animals from the
state's various ecological regions.
Nationwide efforts to address CWD are accelerating rapidly. In other states with captive animals known to have or have been exposed to CWD, management is concentrating on quarantining or depopulating captive or free-ranging animals in the affected area. In some cases
around captive populations, double fencing is recommended to prevent direct contact between captive and wild animals
In wild populations, the management option recommended is to reduce the density of animals in the infected area to slow the transmission of the disease. This is being done by selective culling of animals suspected to have been directly exposed to the disease. In Colorado and Wisconsin, large numbers of animals are being killed to reduce density of animals and thus slow the transmission of the disease. There is still a large need for research on the disease as many questions go unanswered. There is also a need for increased funding to support additional laboratories for testing animals for the disease.
Almost every state wildlife agency is now planning an
increased effort at surveillance to detect if CWD is present. Many state agencies have banned the importation of cervids into the state. Some states have also halted intra-state movement of deer and elk and banned supplemental feeding programs.
What can hunters do?
Hunters should be vigilant when afield for deer or elk that
display abnormal behavior such as staggering or standing with very
poor posture. Animals may have an exaggerated wide posture, or may carry the head and ears lowered. Infected animals become very emaciated (thus wasting disease) and will appear in very poor body condition.
Infected animals will also often stand near water and will consume large amounts of water. Drooling or excessive salivation may be apparent. Report any suspected cases of CWD to the proper authorities immediately.
Hunters should also support Texas efforts to restrict deer or elk importation and report any suspected violations.
Finally, hunters should arm themselves with information, especially practical tips for hunting and field dressing game.
Where can I learn more?
For Texas information, check the Web sites of the Texas Parks and Wildlife Department and the Texas Animal Health Commission for periodic updates.
Various others sites offer information about CWD, including the U.S.D.A. site.
Human health information for transmissible spongiform encephalopathy diseases is on the federal Center for Disease Control and Prevention site.
Some excellent information is available on Web sites of states where CWD has been detected in free-ranging deer:
Colorado - CWD
Nebraska Health Issues - CWD.
In early July, the Chronic Wasting Disease Alliance web site will be up and running.
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