One of the main reasons small operation breeders don't use AKC dogs is because a breeder sold them a dog under an AKC limited registration, meaning the dog wasn't intended to be breeding stock, and the breeder intended for the puppy to be neutered when it was old enough. Sometimes people decide they are not going to get the puppy fixed, and will use it for breeding…at that point, any puppies produced from that dog are not registerable with the AKC. But the other registeries will sign those dogs up with no questions asked.