The disease is caused by an abnormal protein called a prion that affects the brain and nervous system. Diseases associated with prions cause transmissible spongiform encephalopathies or TSEs. TSEs cause small holes to appear in affected brain tissue so that it resembles a sponge (thus spongiform) and brain function deteriorates gradually over time. Other types of prions cause bovine spongiform encephalopathy (BSE), commonly known as “mad cow disease”, scrapie in sheep and goats, and Creutzfeldt-Jakob disease in humans. CWD does not appear to naturally infect cattle. 

Animals infected with CWD may not display symptoms for months to years after infection. In later stages, animals may display symptoms such as weight loss, poor coordination, drooling, stumbling, trembling, and lethargy. It is fatal in all cases; there is no treatment or vaccine. The abnormal prion accumulates in tissues and although it concentrates in tissues of the central nervous system, it can also be present in other organs and muscle tissues. 

Animals can spread the infection without showing symptoms. The disease spreads between animals through prions shed in saliva, urine, other bodily fluids, and carcasses. Prions can also be shed into the environment with the potential to expose other animals indirectly. The infectious prion can survive in the environment for many years.

CWD was first detected in captive deer in Colorado in 1967 and has been spreading across North America in wild and captive animals ever since. It has been detected in Canada in BC, Alberta, Saskatchewan, Manitoba, and Quebec. CWD has been detected in two of the three states bordering BC, Idaho and Montana.

CWD was first detected in BC in the Kootenay region in January 2024. The BC Wildlife Health Program began surveillance for CWD in free-ranging deer, elk, moose, and caribou in 2002.

Learn more about BC’s CWD program and surveillance efforts here.

Hunters and trappers across BC are asked to help monitor for the disease by submitting samples for testing from harvested and collected animals, and reporting sick animals. Anyone observing a sick deer, elk, moose, or caribou exhibiting the symptoms of CWD - thin, drooling, poor coordination, stumbling, or generally sick with no obvious reason - are asked to report it to the 24/7 Report All Poachers and Polluters (RAPP) Line at 1-877-952-7277 or report it to the Provincial Wildlife Health Program at 250-751-3219. 

Hunters that harvest cervids and trappers that collect roadkill are encouraged to take precautions when handling carcasses. Precautions include avoiding handling tissues where prions can be concentrated – these include brain, spinal cord, eyes, tonsils, spleen, and lymph nodes – and to leave these high-risk tissues at the kill site. Hunters are encouraged to have harvested animals tested (mandatory for licensed hunters in high-risk areas) so that provincial experts can confirm disease status in cervid populations of BC. It is recommended to wait for test results before consuming the animal in high-risk areas. Although, CWD is not known to infect humans, domestic animals, or non-cervid livestock, infected meat should not be consumed.

Transport of cervid parts can contribute to spreading the disease. If animals are harvested in known CWD areas, be aware of the risks of transporting this material and potentially introducing CWD to new areas. Leave high-risk tissues at the kill site and take precautions when disposing waste material. If you wish to keep the skull or antlers, remove all brain tissue from the skull and connecting bone plate and disinfect with a 10% bleach solution. If you wish to have a hide tanned, remove all tissues, enclose in a plastic or sealed container, freeze, and submit for tanning as soon as possible.

If you are outside BC, seek information about the CWD situation, surveillance efforts, and regulations in the area where you will be hunting.

CWD has been detected in deer in the Kootenay region of BC. It is important to follow safe food handling practices. The BCCDC provides guidelines for cutting and wrapping of uninspected meat like game meat. Keep uninspected meat separate from inspected meat; labelling the carcass with the name of the owner and where it came from and disposing of waste in a sanitary manner. Butchers are responsible for keeping records of hunted animals processed in their premises per the Wildlife Act section 71.

Butchers are reminded to wear personal protective equipment such as gloves, eyewear, and aprons to limit contact with blood and tissues while cutting hunted meats, and to follow good handwashing, and hygiene practices. All equipment and utensils used in the processing of uninspected meat and meat products should be cleaned, washed, and sanitized immediately after processing, and prior to being used for processing other meat. For more information, please refer to the guidelines.