Chronic Wasting Disease

Copyright© 2010 by Anne Vinnola

  Chronic Wasting Disease is an increasing issue for hunters in the USA and new states such as Virginia are showing up with the problem. With a little education on the subject we can all find ways to combat the spread of CWD and hopefully work together with wildlife agencies begin to find a way to eventually help eradicate the disease from animal populations.

 CWD belongs to a group of diseases known as TSEs or Transmissible Spongiform Encephalopathies or prion diseases. It resembles bovine spongiform encephalopathy (BSE) in cattle (also known as “mad cow disease”) as well as Scrapie identified in sheep for over 200 years, but is a distinctly different condition.

Chronic Wasting Disease (CWD) is a contagious neurological disease affecting deer, elk and moose. CWD causes a spongy degeneration of the brain of the infected animal, resulting in weight loss over weeks or months, excessive salivation, difficulty swallowing, excessive thirst and excessive urination, behavioral changes. In some animals, ataxia and head tremors may occur. Cases of CWD occur most often in adult animals, but also have been found in yearlings.

 It is not known for sure how CWD is transmitted, possibly through feces, urine or saliva. It is thought to be transmitted from animal to animal laterally but can also be transmitted from mother to fetus. 

 According to the Chronic Wasting Disease Alliance, much is being done to address the problem and many states have implemented programs and regulations regarding the transportation of hunter-harvested deer and elk carcasses out of known CWD areas. Some of the strategies for control include; regulations in Colorado that allows only boned meat, quarters (without spinal column or head) or processed meat from deer or elk to be transported out of certain CWD areas.

Another option for managing CWD in wild populations is to reduce the density of animals in the infected area to slow the transmission of the disease. This is done by selective culling of animals suspected to have been exposed to the disease. In Colorado, Nebraska, Wisconsin and Saskatchewan, efforts are underway to drastically reduce local wild cervid populations in an effort to eliminate CWD in areas where it recently was found.

Regulations concerning commercial captive cervid operations vary from state to state. The regulatory authority resides with the state agricultural or animal health agency, in some with the state wildlife management agency, and in some the authority is shared between agricultural and wildlife management agencies. When CWD is detected in a captive cervid facility, generally that facility is quarantined and all captive cervids in that facility are killed.

The WHO, World Health Organization has reviewed the latest research and currently believes that CWD is not transmitted to humans. The WHO website states “It is advised that any tissue which may come from deer or elk with Chronic Wasting Disease (CWD, a transmissible spongiform disease of North American mule deer and elk) is not used in animal or human food; however, at this time there is no evidence to suggest that CWD in deer and elk can be transmitted to humans.”  However, health and wildlife officials advise caution. Hunters are encouraged not to consume meat from animals known to be infected. Hunters should take common sense precautions when field dressing and processing deer or elk taken in areas where CWD is found. A map from the Chronic Wasting Disease Alliance (www.cwd-info.org) shows the affected areas of CWD. MAP

 Some recommended precautions for carcass handling are:

•  Do not shoot, handle or consume any animal that appears sick; contact your local wildlife authorities.
• Wear rubber gloves when field dressing and processing animals.
• Bone the meat from your animal.
• Minimize the handling of brain and spinal tissues, and wash hands.
• Disinfect knives, saws and cutting table surfaces by soaking in a solution of 50 percent chlorine household bleach and 50 percent water for an hour.
• Thoroughly rinse all utensils in water to remove the bleach. Afterward, allow them to air dry.
• Wash hands and instruments thoroughly after field dressing is completed.
• Avoid consuming brain, spinal cord, eyes, spleen, tonsils, pancreas and lymph nodes of harvested animals. Normal field dressing, coupled with boning out a carcass, will remove most, if not all, of these body parts. Cutting away all fatty tissue will remove remaining lymph nodes.
• Do not consume meat or organs from animals known to be infected with CWD.

For more information please contact your local wildlife offices or the Chronic Wasting Disease Alliance at www.cwd-info.org.  The mission of the CWD Alliance is to promote responsible and accurate communications regarding CWD, and to support strategies that effectively control CWD to minimize its impact on wild, free-ranging cervids including deer, elk, and moose.