[3LittleTooties]

There is a lot of great advice here, and I agree that a 3 1/2 lb. dog won't eat much, especially if they are not very active. It won't take much at all to fill up your little guy. I would trust the vet unless there are more symptoms. And, although "shivering" isn't really a common Yorkie behavior, it is something that many little dogs do, so I wouldn't worry about that either so long as everthing else, like drinking, pooping, energy level, and temp. are fine. Best wishes!