While Canadian driving rules are very similar to the U.S. DOT's, there are some minor differences.  Canadian drivers do not carry a medical card since their CDL includes a medical certification.  Additionally, even though they don’t have the same ‘waiver’ program as the U.S., they do have a program in place.  Their CDL includes restrictions such as ‘automatic transmission only’ if a medical condition such as a missing leg exists.  However, the restrictions are not a hard and fast rule for every condition and should not be used in deciding whether to put a driver out of service.  The best rule of thumb if you feel a Canadian driver with a valid CDL has a condition that prevents him/her from legally operating in the U.S. is to contact the Federal Motor Carrier Safety Administration for guidance.