Avoid purchasing your dog or cat at a pet store. Although pet stores are terrific sources of pet supplies, it is usually better to buy your pet from a breeder. If you do buy a dog or cat from a pet store, make certain that it comes with a health guarantee and with registration papers from a respected pet registry. Some of these registries are the American Kennel Club, the United Kennel Club, the Cat Fanciers Association, or the Cat Fanciers Federation or similar organizations.