first of all, I wouldn't ever buy a dog from a pet store. even if they DO have papers from the pet store, most dogs at the pet store come from a puppy mill or backyard breeders. I am not talking about petsmart or petco but just a plain pet store. and I would assume if you bought from a reptuable breeder, the dog would be registered. not that I would ever buy a dog from a pet store or a breeder, I would rather adopt.