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Chronic wasting disease in cervids

If you see a wild cervid with an unusual appearance or behaviour, please tell a wildlife protection agent by contacting SOS Poaching This hyperlink will open in a new window. .


Chronic wasting disease (CWD) is a degenerative disease of the central nervous system that affects cervids such as white-tailed deer and moose. It belongs to the same family as bovine spongiform encephalopathy (mad cow disease) in cattle and scrapie in sheep. These diseases are not caused by a virus or bacteria, but rather by the presence of an abnormally formed protein, a prion, in the animal’s body. Abnormal prions accumulate in nerve cells until they burst. As the animal’s nerve cells are destroyed, signs of the disease appear and worsen to the point of causing the animal's death in 100% of cases.

Animals at risk

Chronic wasting disease (CWD) only affects cervids such as white-tailed deer, red deer, elk, mule deer, moose and caribou.

According to current data, moose only seem to contract CWD when they share their territory with another species (e.g., white-tailed deer) in which the disease is well established.

In Québec, CWD cases were detected in 2018 on a red deer farm in the Laurentides region. Following this discovery, intensive culling efforts were conducted to reduce the deer population and thus avoid the establishment of the disease among wild cervids. An enhanced surveillance area was also put into place to quickly detect any outbreak of the disease among wild cervids in the targeted area. Facilities that has come into contact with the infected Laurentides farm are maintained under sanitary measures.

Signs of the disease in animals

Physical manifestations of chronic wasting disease (CWD) can mostly be seen during the disease's terminal stage. Only the analysis of the brain and lymph nodes located at the base of the jaw of an animal infected for more than 12 months can confirm the diagnosis. Currently available tests are not sensitive enough to detect abnormal prions in newly affected animals.

Samples submitted for CWD detection (obex and retropharyngeal lymph nodes) can only be collected on dead animals. The following symptoms may be present in a cervid infected by CWD after several months:

  • drastic weight loss and deterioration of physical condition;
  • excessive salivation and urination;
  • subtle head tremors;
  • lowered head and ears;
  • splayed legs;
  • dull, pale, and spiky coat (the animal may keep its winter coat much longer than normal);
  • aggressiveness, panic, or other abnormal behaviour;
  • lack of coordination, paralysis.

Transmission and incubation period

We do not know precisely every mode of transmission of chronic wasting disease (CWD). The most significant transmission routes would trace back to an environment that is contaminated by urine, feces, saliva or blood from infected animals and direct contact between cervids. The prion is highly resistant and can remain in an environment for several years.

The disease can spread geographically by the movement of live infected cervids, the transportation of carcasses or parts of carcasses of infected cervids and the use of products from infected animals (e.g., urine).

The disease can be transmitted from wild to captive cervids and vice versa. It appears to spread more rapidly in areas where high concentrations of cervids are found, such as on captive facilities and in feeding and baiting areas.

CWD is spreading across North America. It is now found in 26 U.S. states as well as in the provinces of Alberta and Saskatchewan.

Delay between the entry of the prion into the animal’s body and the onset of the disease

Physical manifestations of CWD typically occur 16 to 36 months after the animal has contracted the disease. During this time, cervids show no signs of the disease, but they can transmit it.


There are no treatments or vaccines for prion diseases. Chronic wasting disease (CWD) is always lethal for infected cervids. Death generally occurs within weeks or months following the onset of symptoms.

Once CWD is introduced into a wild population, it is extremely difficult to eliminate.

Protection and prevention

There is currently no scientific evidence to suggest that chronic wasting disease (CWD) can be transmitted to humans. However, Health Canada recommends not to consume the meat or products of an infected animal.

It is important to always comply with the best practices for handling and preserving game meat, as well as safety standards for cutting the meat. For more information, you may refer to this document on wild game meat (in French only) This hyperlink will open in a new window.. At all times, it is recommended not to consume cervid’s brain, spinal cord or lymph nodes. Please note that cooking does not destroy the prion.

In livestock

All cervids over 12 months old slaughtered in federally and provincially inspected establishments are tested for CWD. No diseased animals are introduced into the food chain.

To prevent the introduction of the disease in Québec, the import of farmed cervids is legally regulated by the Protocol respecting the importation of cervids into Québec from other provinces or countries and the Regulation respecting animals in captivity.

For operators who want to export products or animals outside of Québec, the Chronic Wasting Disease Herd Certification Program (CWD HCP) ensures to potential buyers that two herds with the same rating present identical risks regarding CWD.

In wild animals

The chronic wasting disease (CWD) invariably kills infected animals and, once established in an area, can significantly impact deer herds, their health, and eventually the viability of local populations. For example, in Wyoming, a 10% per year decrease in the white-tailed deer population has been observed since the disease became established in wildlife.

In Québec, regulations, as well as surveillance and control operations, help reduce the disease's risk of establishment in wildlife.

Hunters in affected areas in Outaouais, Laurentides and Montérégie are invited to learn more about the wildlife surveillance program to find out the details on white-tailed deer analysis. In other regions of Québec, some butcher shops also take part in the surveillance network.

CWD is a notifiable disease for the Ministère de l’Agriculture, des Pêcheries et de l’Alimentation du Québec, the Ministère des Forêts, de la Faune et des Parcs and the Canadian Food Inspection Agency.

If you are hunting outside of Québec

Avoid hunting in or near areas where CWD was detected. Whole carcasses, as well as some anatomical parts (e.g., brain, spine, eyes, internal organs), cannot be brought back to Québec.

If you are notified by authorities in the province or state where you harvested a cervid that your game has CWD, please inform a wildlife protection agent by contacting SOS Poaching This hyperlink will open in a new window..

To know which states and provinces are affected by CWD, refer to the Distribution of Chronic Wasting Disease in North America map This hyperlink will open in a new window..

Farms management

Regulations and certification program for livestock

The Chronic Wasting Disease (CWD) Herd Certification Program allows cervid owners to have their herd recognized as an elite herd regarding CWD. For animal buyers, this program ensures that two herds with the same rating present identical infection risks for the disease. The level of assurance with which the herd is deemed exempt from CWD depends on the length of time since it was enrolled in the program.

The program standards This hyperlink will open in a new window. set by the Canadian Food Inspection Agency (CFIA) were tightened in 2017. Operators whose herd enrollment anniversary date is beyond March 31, 2018, must comply with the new standards.

To enroll in the program or for more information, please contact the Canadian Sheep Federation, the regional administrator and status assessor for Québec.

Contact person: Julia Patterson

Toll-free phone number: 1-888-684-7739

Local phone number: 1-613-652-1824 or CWD@Cansheep.ca

The list of enrolled producers and documents needed to enroll in the program are available here: https://www.cansheep.ca/cwd.html This hyperlink will open in a new window..

Cervid importation protocol

Cervids coming from other provinces or countries must comply with the requirements in effect in Québec to enter the province. The requirements are presented in the Protocol respecting the importation of cervids into Québec from other provinces or countries (PDF 153 Kb) and the Regulation respecting animals in captivity.

Transportation of farmed cervids in Québec

Any operator wishing to transport farmed cervids temporarily or permanently must obtain a transportation permit from the Canadian Food Inspection Agency.

Current regulations prohibit the transportation of a cervid in captivity located under 100 km from a site where CWD was detected, except for transporting outside of the province or to a slaughterhouse.

Last update: June 13, 2022


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