Department continues actions to protect deer and elk herds from chronic wasting disease: Hunters asked to assist in surveillance efforts

Arizona wildlife officials continue to be on the lookout for a silent killer of deer and elk. It hasn’t reached Arizona yet, but could possibly arrive here someday. It’s called chronic wasting disease (CWD), and although it has not been found to affect humans, it is fatal to deer and elk.

Signs of CWD in deer and elk include low weight, stumbling gait, drooping ears, rough hair condition, visible salivation, excessive thirst, and loss of fear of humans.

“Although we haven’t had a confirmed case in Arizona, we’ve been studying and preparing for this disease for years,” says Jim deVos, research branch chief for the Arizona Game and Fish Department. “It’s in several other western states, including three that border Arizona. We’ve taken steps to try to keep it out of the state, and have a plan in place to deal with it if it arrives.”

The effort to deal with CWD requires the support of sportsmen. Here is some information that every hunter should know about CWD.

How can hunters help protect our deer and elk herds? Bring in the head of recently harvested deer or elk to any office of the Arizona Game and Fish Department between 8 a.m. and 5 p.m., Monday through Friday. Addresses are listed on the department’s Web site. Place the head in a heavy plastic garbage bag for delivery. Keep the head cool and out of the sun if possible.

To better assist the surveillance effort, you will be asked to fill out a form when you drop off your deer or elk head. Please include the following information: county and game management unit in which the animal was harvested, hunt number and permit number, and a phone number where you can be reached. Note: If this information is not provided, the department will be unable to test the head.

You will be notified of CWD test results by postcard within six to eight weeks. There is no charge to you for the testing and notification.

What is chronic wasting disease?

CWD is a wildlife disease that affects deer and elk. It belongs to a family of diseases called transmissible spongiform encephalopathies (TSEs), which attack the brain and turn it into a sponge-like material. Other TSEs are mad cow disease in cattle, scrapie in sheep, and Creutzfeldt-Jakob disease in humans.

CWD is thought to be caused by mutant proteins called prions. Scientists believe the disease may be spread both by animal-to-animal contact and by soil or other surfaces to the animals. It is thought that the most common modes of transmission are via saliva and feces.

When was CWD first discovered?

Researchers discovered CWD in the late 1960s in captive deer at a Colorado wildlife research facility. Initially, the disease appeared to be confined to deer in research facilities and game farms in limited areas of Colorado and Wyoming. Since then, it has been found in captive and wild deer and elk in other states in the West and Midwest, and recently in some eastern states.

What is the Game and Fish Department doing about CWD?

Because CWD has not yet been found in Arizona, we have focused on three things: (1) reducing the chance of the disease entering Arizona, (2) watching carefully to ensure early detection, and (3) planning on how to deal with it if it arrives.

In 2002 the Arizona Game and Fish Commission introduced emergency rules (now permanent) prohibiting the importation of live deer and elk into Arizona, and restricting the movement of deer and elk within the state. Captive deer and elk are subject to marking and reporting requirements. The department has also been advising hunters of precautions to take when bringing back harvested deer or elk into Arizona from other states (visit our CWD Web page for a list of these precautions).

Surveillance is an extremely important component of the plan to deal with CWD. “Aggressive monitoring is essential,” says deVos. “The earlier the disease can be detected in an area, the better. Once CWD becomes established, particularly in areas with high population densities of deer and elk, it can be extremely difficult to eradicate.”

The department has been conducting surveillance efforts since 1998. All department personnel have been trained to recognize clinical signs of CWD. In addition, an extensive testing program has resulted in the examination of 3,500 samples, primarily from hunter-harvested deer and elk, with no positive cases of CWD detected in Arizona. Testing involves taking brain stem (obex) tissue or lymph node samples and sending them to a special lab for evaluation. There is no practical way to test live animals for the disease at the current time.

If CWD is found in Arizona, the Arizona Game and Fish Department has developed a comprehensive CWD management plan. The action steps for responding to a CWD-positive test depend on a number of variables, including where the disease is found, how prevalent the disease is in that area, population density of deer and elk in the area, and other factors. Potential actions include intensified testing and possible herd reductions in the affected region to reduce the risk of spread of the disease.

Is chronic wasting disease a threat to humans?

No evidence has been found to indicate that CWD affects humans, according to both the U.S. Centers for Disease Control and Prevention and the World Health Organization.

Occasionally, unsubstantiated rumors surface that suggest eating CWD-infected game meat can cause Creutzfeldt-Jakob disease, a TSE that occurs in humans. There are two forms of Creutzfeldt-Jakob disease: conventional and variant. The Centers for Disease Control and Prevention says conventional Creutzfeldt-Jakob disease occurs randomly throughout the world in one out of every one million people over the age of 65. Variant Creutzfeldt-Jakob disease has been associated with the domestic livestock disease Bovine Spongiform Encephalopathy (also called “mad cow disease”).

The Centers for Disease Control and Prevention has reviewed the best available science and says there is no evidence that CWD can cause either form of Creutzfeldt-Jakob disease. In two states where CWD has been present in wildlife for years, Colorado and Wyoming, there has not been an increase in the incidence of Creutzfeldt-Jakob disease in humans.

While science has not shown evidence of a connection, common sense would suggest that hunters avoid harvesting or eating meat from any animal that appears to be sick. Take precautions when field dressing an animal, including wearing rubber gloves, boning out the meat from your animal, and minimizing the handling of brain and spinal tissues.

Team effort needed

Healthy deer and elk populations are important to Arizona. We all have a stake in doing our part to be informed of and watchful for this disease. If you see a deer or elk with signs of sickness that you think could be CWD, contact the Arizona Game and Fish Department at 1-800-352-0700.

For more information on CWD, visit the Arizona Game and Fish Department’s Web site (link: the Chronic Wasting Disease Alliance Web site.(link: For more information about CWD and Creutzfeldt-Jakob disease, visit the Centers for Disease Control and Prevention Web site.(link: Use their search feature to search the site for chronic wasting disease.

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