A reader called asking for the name and phone number of an AKC breeder for her selected breed. She stated that she knew that if the dog is registered and costs a lot, it means that the dog can be shown and bred and will always be healthy.
I explained that even the pups from the highest ranked champions cannot have a guarantee that they will follow in their parents' footsteps. That is the reason that responsible dog breeders will have a clause in the contract that if the pup does not grow and perform as expected, the breeder will accept the animal back.
Some other health problems that may not be noticeable in a young pup are: faulty heart or the pituitary gland can shut down (one of my dogs had that happen and she drank gallons of water a day until she got the hormone shots). Another one of my dogs, a conformation champion, developed "dry eye." For the rest of his life he had to be treated two or three times a day with an eye ointment. I did not consider him good enough to be used for breeding because he had several health problems that developed after he earned his championship.