Chronic wasting disease

Overview

Chronic wasting disease (CWD) is a fatal and untreatable disease that affects the central nervous system of members of the deer family or “cervids” (such as white-tailed deer, American elk, moose and woodland caribou). There is no cure and no vaccine to prevent it. CWD has the potential to severely reduce cervids populations.

CWD is caused by infectious abnormal proteins called prions, which accumulate in the brain and other tissues leading to death. CWD is in the same family of diseases as scrapie in sheep, bovine spongiform encephalopathy (BSE) in cattle (also known as “mad cow disease”) and Creutzfeldt-Jakob disease in humans.

CWD is highly contagious and can be spread through the saliva, urine, feces and blood of infected animals, or by exposure to a contaminated environment. There is evidence the disease may remain infectious in the environment, such as in soil, for years.

Chronic wasting disease was originally discovered in Colorado in 1967. Since then, it has been detected in over 33 US states and 5 Canadian provinces (Alberta, Saskatchewan, Québec, Manitoba and British Columbia). It has been found in both provinces and all US states that share a border with Ontario.

It has also been found in South Korea and, more recently, Norway, Sweden and Finland. Once present in wild cervids, it is very difficult to stop its spread.

We have been monitoring deer in Ontario since 2002, tested over 15,300 samples and have found no evidence that the disease is present in Ontario wildlife, but it’s important to be vigilant. CWD would harm wildlife and the economy.

Download CWD Infographic (PDF)

Chronic wasting disease prevention and response plan

Our chronic wasting disease prevention and response plan was updated in 2019 to reflect current scientific knowledge, lessons learned from other jurisdictions, and the evolving roles of government agencies.

The plan sets out an adaptive, coordinated approach to the actions we are taking in partnership with other agencies to:

• minimize the threat posed by CWD
• protect the significant socio-economic, cultural and ecological benefits provided by Ontario’s wild deer, moose, elk and caribou

Read our Chronic wasting disease prevention and response plan.

Keeping chronic wasting disease out of Ontario

We have a number of measures in place to reduce the risk of chronic wasting disease entering Ontario.

Hunting

When hunting, do not use attractants or lures made from cervids. Instead, use artificial or plant-based products.

Attractants and lures made from cervids are illegal to have and use in Ontario. They may contain infectious material and could introduce chronic wasting disease to Ontario.

Contact your local ministry work centre for more information.

Restrictions on importing and moving live cervids

Effective January 1, 2021, the:

• import of all species of live captive cervids into Ontario from other provinces, states or territories is prohibited, unless authorized by a ministry-issued permit
• movement and transportation of live captive cervids between points within Ontario is prohibited, unless authorized by a ministry-issued permit

Learn about applying for a permit to import or move live captive cervids.

You must immediately report any escape or release of captive deer or elk to the ministry. The owner of escaped captive deer and elk may be liable for all costs incurred by the ministry to recover or remove the animals.

Hunting outside of Ontario

Stay up to date on the latest hunting regulations. Detailed regulations related to transporting animal body parts are in Section 4 of Ontario Regulation 666/98.

New regulations came into effect January 1, 2021 to help reduce the risk of CWD coming into Ontario through imported cervid body parts hunted in other provinces, states or territories.

If you hunt cervids out of province, you can only bring back to Ontario:

• butchered, deboned and packaged meat
• a cleaned skull plate and antlers
• tanned hides and capes
• finished taxidermy mounts

It’s illegal to bring any other body parts from deer species into Ontario. These rules apply to all members of the deer family, or cervids, which comprise more than 37 species.

All imported parts must be clean of all other tissue and labelled with the:

• species name
• name and address of the owner
• location where the imported parts came from

Any unwanted parts must be disposed of at a facility authorized to receive animal waste and parts.

Hunters who have any part of a cervid that was transported into Ontario, and has also tested positive for CWD, must:

• let us know by calling or emailing your local ministry work centre
• dispose of the parts according to our direction

Non-resident transport

Non-residents of Ontario may temporarily import raw hides, antlers, teeth, skulls, unprocessed meat and skin of the head from deer species through Ontario if the:

• parts are in temporary transit through Ontario enroute to another province or state
• parts are kept in a sealed container from which nothing can escape
• container is labelled with the species, name and address of the owner
• container is labeled with the location where the imported parts came from

Signs

Chronic wasting disease (CWD) is a progressive disease meaning that an infected animal may appear normal for several years before signs of illness develop.

Animals infected with CWD may exhibit:

• severe loss of body weight and body condition
• abnormal behaviour, such as indifference to human activity
• tremors, stumbling, lack of coordination or paralysis
• excessive drinking and urination
• excessive salivation/drooling
• drooping head/ears
• Note:
  • infected cervids may not show signs for several years
  • some of these individual signs may be seen in other diseases

If you observe these signs in a wild cervid, note the location of the animal, and if possible:

• take photographs or video from a safe distance and contact your local ministry work centre or email CWD@ontario.ca

Testing

Monitoring is key to the early detection of chronic wasting disease (CWD) should it enter Ontario. Hunter participation in the surveillance program, by submitting heads of harvested deer for testing, is critical to Ontario’s efforts to detect CWD.

Since 2002, each year, the ministry CWD surveillance program takes samples from hunter-harvested deer in areas with the highest risk of chronic wasting disease. Sampling locations vary from year to year. Locations are chosen based on the following known risk factors:

• proximity to neighbouring outbreaks
• deer and elk population density
• presence of cervid farms
• prior sampling effort
• winter deer feeding areas
• winter severity

Hunters who harvest a deer from a wildlife management unit within a surveillance area can have the animal tested free of charge by the ministry. Fawns under 1 year of age will not be tested as CWD is less likely to be detected in young animals.

For more information on this program or to submit a sample from one of the surveillance areas, call our wildlife health information line at 1-888-574-6656.

Testing procedures

There are currently no approved live tests (such as blood test) available that can definitively diagnose CWD. At this time, CWD infection can only be confirmed by testing tissue from an animal after it is dead.

In selected regions during firearm hunts, roving crews of ministry wildlife research technicians visit hunt camps and request samples from harvested deer. The research technicians will ask the hunter’s permission to remove a small amount of tissue from the base of the skull of the deer for analysis. The deer will then be returned to the hunter. Sampling will not prevent hunters from consuming the meat or having the head mounted. Read chronic wasting disease and human health section for more information.

We also need samples from archery hunters and gun hunters who are not contacted by the roving crews. These hunters are asked to take the heads of yearling or older deer they harvest and deposit them in one of the ministry freezer depots. When submitting heads, hunters:

• are required to provide the date and location of the harvest
• should make deposits as soon as possible, preferably within 48 hours of harvest or freeze the head until it can be dropped off
• should remove the antlers before submission
• may remove the skull cap as long as the majority of the brain, including all of the brain stem, remains in the head

Note: If a hunter fails to provide complete information, the sample will not be tested.

The first 500 hunters in each surveillance area who provide a tissue sample from a deer taken in a surveillance area will receive participation crest.

2024 testing and freezer locations

In 2024, we will conduct chronic wasting disease monitoring in 2 Ontario regions:

• Southern Ontario: wildlife management units: 81A, 81B, 82A, 82B, 82C, 84, 85B
• Southern Ontario: wildlife management units: 68A, 71, 74A, 74B

The 2024 freezer locations will be updated prior to the hunting season. Continue to check this page for regular updates.

2024 surveillance areas, Southern Ontario

If you have a deer from a designated wildlife management unit you’d like to have sampled, but you are unable to submit it at a freezer location, please contact us.

Hunters can expect their deer samples to be tested within 2-8 weeks. Samples submitted via depots may take longer to be processed. Test results will be posted in the test results table.

Test results

Explanation of results

Chronic Wasting Disease not detected

Chronic Wasting Disease was not detected in the sample

Sample not tested

It was not possible to test this sample or the sample was from outside of the surveillance zone

For more information on the ministry surveillance program, or to receive copies of the previous year’s report, please contact us.

Chronic wasting disease and human health

There is currently no definitive scientific evidence to suggest that chronic wasting disease is transmissible to humans, and there have been no reported cases of CWD infection in humans.

Early results of long-term research on transmission of CWD to macaque monkeys (a species closely related to humans) suggests that transmission to this species may be possible. While research continues, it is important to be cautious.

As a precaution, public health officials including Health Canada and the World Health Organization recommend taking proper precautions when handling cervid carcasses and avoiding exposure to, and consumption of, CWD-infected animals.

Handling wildlife carcasses

When handling and processing Ontario deer, elk and moose, it is suggested that hunters:

• wear latex or rubber gloves and eye protection when field dressing carcasses
• minimize the handling of brain, eyes, and spinal tissue as this is where the highest concentration of CWD prions, if present would be found
• minimize the handling of bones of the skull and spinal cord
• don’t consume the brain, spinal cord, eyes, spleen, tonsils or lymph nodes of harvested animals
• decontaminate your tools by removing organic material and then soaking tools for at least 5 minutes in a 40% household bleach solution
• if you are hunting within a CWD surveillance zone, save the head and submit it for CWD testing

Related

• Fish and wildlife health
• Wildlife research and monitoring
• Chronic wasting disease permit system
• Updates on emerging fish and wildlife diseases