Monitoring and testing for chronic wasting disease
Learn about the chronic wasting disease (CWD) surveillance program, how to have your deer tested and get your test results.
Monitoring chronic wasting disease
We are continuing our surveillance measures to monitor wildlife for chronic wasting disease.
If you observe these signs in a wild cervid (member of the deer family), contact your local ministry work centre or email CWD@ontario.ca.
Surveillance program
Monitoring is key to the early detection of chronic wasting disease (CWD).
Since 2002, our annual CWD surveillance program takes samples from hunter-harvested deer in areas with the highest risk of chronic wasting disease.
Hunters who participate by submitting heads of harvested deer for testing are critical to Ontario’s efforts to detect CWD.
Sampling locations vary each 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.
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 the ministry’s wildlife health information line at
Program testing results to date
CWD surveillance has been ongoing in Ontario since 2002. Over 16,000 samples have been tested since then. CWD has not been detected in any sample.
However, we must remain vigilant because CWD has been detected:
- in Manitoba and Québec, very close to the Ontario border
- in all 5 US states that share a border with Ontario
Testing procedures
There are currently no approved live tests (such as a blood test) available that can definitively diagnose CWD.
CWD infection can only be confirmed by testing tissue from an animal after it is dead.
Testing by ministry roving crews
In selected regions during portions of the firearm hunts, roving crews of ministry wildlife technicians visit hunt camps and request samples from harvested deer.
The 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.
How to submit a deer sample for testing
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 general location of the harvest, otherwise the sample will not be tested
- 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
If you have a deer from a designated wildlife management unit that you would like to have sampled, but you are unable to submit it at a freezer location, please contact us at CWD@ontario.ca.
Hunters can expect their samples to be tested within 4 to 8 weeks. Samples submitted via depots may take longer to be processed.
Test results will be posted in the test results table on this page.
Earn your crest
The first 500 hunters in each surveillance area who provide a tissue sample from a deer taken in a surveillance area will receive a participation crest.
2025 testing and freezer locations
In 2025, we will conduct chronic wasting disease monitoring in 2 Ontario regions:
- Central Ontario in Wildlife Management Units (WMUs): 56, 60, 62, 75, 76A, 76B and 76E.
- Southwestern Ontario in WMUs: 94A and 94B.
The 2025 freezer locations will be posted prior to the hunting season. Continue to check the website for regular updates.
2025 sampling area, Central Ontario
2025 sampling area, Southwestern Ontario
Test results
Testing for 2024 is now complete; results are available. CWD was not detected in any samples.
Explanation of results
- CWD not detected
- CWD 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.