As per City of Toronto rideshare regulations, you must serve any and all persons with service animals. A service animal is not a pet. It is against the law to:
(1) Refuse to serve the person;
(2) Refuse to permit the person and the service animal to enter the licensed vehicle;
(3) Refuse to permit the person and service animal to remain in the vehicle.
Allowing or disallowing persons with pets (non-service animals) is at the discretion of you as the driver of the vehicle. If you feel comfortable allowing a pet in your vehicle you are more than welcome to but if you do not want to you are not expected to do so.
Tip: Keep a blanket in your trunk and place it on the seat before a service animal enters the vehicle.