https://files.ontario.ca/books/mnrf-2021-hunting-regulations-summary-en-2021-04-01-v2.pdf
2021 Hunting Regulations Summary
Dogs
All dogs used to hunt deer, moose or black bear must be licensed for the purposes of hunting. There are some areas where dogs are not permitted to be used for hunting deer or moose (see the season tables of the Deer and Moose sections for additional details). Dogs may not be used to hunt elk.
Dogs are not permitted to run at large in areas usually inhabited by big game during the closed season. It is your responsibility to ensure your dog does not enter private property that you do not have permission to hunt on or where hunting is prohibited in contravention of the Trespass to Property Act. Hunters are responsible for ensuring their dogs are under their control and that hunting activities are conducted lawfully.
During lawful hunting hours, you are permitted to use a leashed dog (dog does not require a licence) to track and retrieve wounded big game during the open season provided the dog is kept on a leash that has a maximum length of 10 metres and the dog is under the physical control of the dog handler at all times. The licensed hunter who wounded the animal must be with the dog and handler, and if party hunting, the holder of the tag must also be present. The person handling the tracking dog must not be carrying a firearm unless properly licensed to hunt the animal being tracked.