If it was chocolate or he looks sick and really not acting himself.. take him to the vet. If he is just lazy.. he could just be having "one of those days". Did ya give him a lot of exercise or something?

Dogs and puppies eat the strangest things that you would think would make them get sick... licking the floor and things outside? you know all those germs and disgusting things? If you are very unsettled... take the dog to the vet.. no harm can come just by going, eh?

but curious.. what kind of candy was it?