Ive only ever been asked for rabies, if anything at all. It would probably be a good idea to ask your vet for a printout of their recent vaccines/vet visits just to have on hand in case they ask for more than the rabies, but usually they arent fussed about it. Canadian customs agents in general are much more easy going than US, and since you live on the american side they arent likely to give you any problems coming back anyway.