A written contract serves to support and protect the buyer, the breeder, and most of all- the puppy. A good contract will affirm certain things- like a health guarantee that states the puppy is healthy, free of communicable disease and current on immunization. The written contract may include spay/neuter requirements appropriate to your puppy as well as an agreement to provide appropriate care (good food, training, exercise and veterinarian care). A good breeder will always take back a dog if the buyer becomes unable to care for it.