Chronic Wasting Disease (CWD)
With the recent (Oct 2012) confirmation of Chronic Wasting Disease (CWD) in a Pennsylvania deer, the Division of Fisheries and Wildlife (MassWildlife) is reminding hunters that it is illegal to import intact deer carcasses from CWD-positive jurisdictions such as Pennsylvania and New York, into Massachusetts.
What is Chronic Wasting Disease (CWD)?
Chronic Wasting Disease (CWD) is a contagious neurological disease that is fatal to deer, elk, and moose (cervids). It is classified as a transmissible spongiform encephalopathy or TSE. It attacks the brains of infected animals, resulting in their becoming emaciated, exhibiting abnormal behavior and eventually dying. Related animal diseases include scrapie, which has been identified in sheep for over 250 years and "mad cow disease" in cattle.
Where has CWD been found?
CWD has most recently discovered in Pennsylvania in early October of 2012.
At this time (October 2012) CWD has been detected in wild and/or captive cervids (deer, elk, and moose) in 24 states and provinces: Alberta, Canada; Colorado; Iowa; Illinois; Kansas; Maryland; Michigan; Minnesota; Missouri; Montana; Nebraska; New Mexico; North Dakota; New York; Oklahoma; Pennsylvania; Saskatchewan, Canada; South Dakota; Texas; Utah; Virginia; West Virginia; Wisconsin; and Wyoming. Click here for a map of CWD in North America.
Does CWD Pose a Risk to People?
Information to date from the federal Centers for Disease Control (CDC) and the World Health Organization (WHO) indicates that people, cattle and other livestock are resistant to transmission of CWD. There have been no verified cases of people getting the human form of TSE known as Creutzfeldt-Jakob Disease (CJD or variant CJD) from exposure to CWD, even though hunters have been taking and eating deer, elk and moose from the infected areas of Colorado and Wyoming for more than 30 years. New cases of CJD continue to be investigated. While CWD is not known to be present in Massachusetts and appears to pose no known threat to human health, hunters can take some simple precautions to minimize possible exposure to CWD and other common wildlife diseases.
What are the Signs of CWD in Deer?
Symptoms of CWD in deer include excessive drooling, excessive thirst, frequent urination, sluggish behavior, isolation from herd, may walk repetitive courses, grinding teeth, holding head in a lowered position, poor body condition, ribs showing, and drooping ears. Sick deer may be found close to water. Hunters should realize that deer are subject to a variety of illnesses and injuries that may cause unusual behavior or appearance. Please note that some of these symptoms can be seen in deer after a very severe winter when deer may appear very thin and weak, or after a deer has been struck by a vehicle. Rabies, which is rare in deer, may also produce some symptoms similar to those associated with CWD.
Click here for a brochure (pdf--1MB) with pictures of healthy deer compared to one with CWD.
How is CWD Transmitted Among Cervids?
CWD is not the result of virus or bacterial agent. It is caused and transmitted via abnormal proteins called prions. These prions are infectious. Current research indicates that the most likely modes of transmission are though physical contact, environmental contact, or infected feed. Physical contact includes nose to nose contact and nose to decaying carcass. Environmental contact includes an area where a carcass has decomposed, blood, saliva, feces, or soil where it can persist after being exposed to the abnormal prion. Abnormal prions tend to be most concentrated in nervous system tissue (such as the brain) or in lymphatic tissue (such as the lymph nodes) in deer and moose. Other affected tissues and organs include the eyes, spinal cord, tonsils, pancreas, and spleen. Research to date indicates that prions do not accumulate in muscle tissue and hence boned out meat appears to be safe to consume.
Why is the Division of Fisheries and Wildlife Concerned About CWD?
It is the Division's mission to be good stewards of all native wildlife. We strive to keep wildlife populations healthy and in balance with their habitat. CWD is a serious issue. If CWD is detected in Massachusetts, it can affect the health of our wild and captive deer and wild moose populations. Our strongest desire is to prevent the disease from entering our borders. This is why we have put strong regulations in place to prevent the disease from entering Massachusetts.
Click here for advisory regarding Massachusetts Regulations on Importation of Live Deer and Deer Meat.
What is the DFW Plan?
At the present time it is prudent to strive for the "most protective" measures possible. Specific objectives for Massachusetts include 1) disease prevention, 2) early detection and 3) disease control if CWD is found in Massachusetts.
To accomplish these objectives, MassWildlife has been working with the Mass. Department of Agricultural Resources, the Northeast Deer Technical Committee and federal agencies. It is hoped that the following protective measures will minimize the risk of CWD entering the Commonwealth by reducing the chances of a CWD-infected animal entering the state and possibly infecting our wild or captive deer.
- Currently, no live deer, of any species, may be brought into Massachusetts for any purpose. This ban includes animals used in deer farming practices and those used seasonally for petting zoos or holiday displays.
- Also, it is illegal for anyone to import, process or possess whole carcasses or parts of cervids (from wild or captive herds) from states and Canadian provinces where CWD has been detected. The only exceptions to the regulations are meat that is deboned, cleaned skull caps, hides without the head, or a fixed taxidermy mount.
A surveillance and monitoring program was developed and implemented to detect the disease as early as possible. Samples of hunter-harvested and roadkill deer from around the Commonwealth have been tested for CWD by MassWildlife biologists since the 2002 fall hunting season. To date, there has been no evidence of CWD found in the samples taken during the past deer seasons.
Currently, MassWildlife is now only testing deer or moose showing symptoms of CWD or other diseases.
Advice to Hunters
There is no need for alarm as CWD has not been found in Massachusetts and has not been shown to be transmissible to humans. However, Bay State hunters field-dressing or butchering deer should take the same precautions as they might to protect against other pathogens or diseases.
Deer Hunters Who Hunt in Other States or Canadian Provinces
- Check to see if the state or province where you will be hunting has had deer testing positive for CWD. Click here for a map of CWD in North America.
- Check that state/province's regulations regarding the handling of deer and deer parts.
- Comply with the new Massachusetts regulations regarding the importation
of deer meat and deer parts.
Deer Hunters Who Hunt in Massachusetts
- Avoid shooting or handling a deer that appears sick. Please contact MassWildlife if you observe such an animal.
- Wear rubber gloves when gutting or butchering deer.
- Never eat a deer's brain, eyeballs, spinal cord, spleen, or lymph nodes.
- De-bone the deer (remove the meat from the bones and spinal column).
- Avoid cutting through bones or the spinal column.
- If you saw off antlers or through a bone, or if you sever the spinal column with a knife, be sure to disinfect those tools prior to using them for the butchering or removal of meat.
- Remove all fat, membranes and connective tissue from the meat. Note that normal field dressing and trimming of fat from meat will remove lymph nodes.
- Use a 50/50 solution of household chlorine bleach and water to disinfect tools and work surfaces
- Use caution when spreading urine based scents since it is not known if commercial deer lures and scents pose a risk of spreading CWD.
If you hunt deer, elk or moose in other states and provinces, particularly those in which CWD has been detected, hunters should check with that state fish and wildlife agency to see if there is any specific advice to hunters or special regulations. MassWildlife's regulations are similar to other northeastern states, but not identical. Animals lawfully killed in accordance with other states' regulations may be brought to Massachusetts. MassWildlife regulations require, if hunting in a state or province that has tested CWD positive, that you return from your hunt with only boned-out meat hardened antlers with a clean skull cap, hide without the head, or, a fixed taxidermy mount.
Advice to Landowners
Please Do Not Feed Deer! Everyone should be aware that the artificially high deer densities associated with feeding create the potential for increased spread and prevalence of CWD both from infected feed and close contact among individual deer. Deer feeding provides no benefits to deer but adds significantly to the risk that diseases could be spread more quickly and widely.
What Sources Exist for Further Information?
The Chronic Wasting Disease Alliance has developed a web site which is acting as a national clearing house for the most up-to-date and accurate information on CWD. There is an abundance of information available on that site and it offers many links to other sites including state and federal agencies and non-governmental organizations that are involved with CWD management or research.
Links to Other States/Entities
- New Hampshire
- New York
- West Virginia
- CWD Alliance
National Wildlife Health Center
Click here for all MassWildlife CWD Advisories