As it has been stated there is just no way that you can know for sure that you are buying a disease free and defect free pup. However, staying away from breeders whose claim to fame is how small their dogs are is a good start in the right direction. That type of breeder is not doing genetic testing and probably has no clue about what genetic issues were produced by the ancestors of their dogs. They are concentrating on size and not the total breed standard. Line breeding and in breeding is being done to attain a tiny dog but at the same time defective genes are being brought forward with every breeding. Those breeders are not investing money in testing and will not offer a contract that will attempt to treat you fairly. As others have stated many of the genetic issues that you could face are not obvious at 3 months or even 10 months of age so their contract is basically telling you that you have a live puppy. In the end you have to ask yourself if the breeder is going to be there for you if you do face some problem in the future.
I'm sure that those who breed for size have produced some puppies that were healthy but the odds of that happening continue to decrease as they spin the genetic roulette wheel. Personally, I would much rather buy from a breeder that is doing everything they can to produce a puppy that is genetically sound and as close to the breed standard as possible. It's not an easy thing to do and good breeders are watching others exploit the Yorkshire Terrier without regard to the long term health and soundness of the breed. I would find that heartbreaking. Wouldn't you rather support someone who is trying to improve the breed and who has sound and proven bloodlines than someone who is breeding for profit only? |