I often laugh at the breed people assign to puppies. It is very difficult to tell what mixes are included in a puppy under 3-4 months of age. So much easier to see when you monitor body changes as they mature, but it's still a best guess.
One problem with genetic problems is that many don't manifest until the dogs are older. Many have gone through multiple breeding cycles, some have already ended their breeding life when the disease/condition appears.
This is where the genetic markers and testing can really benefit because we can get a handle before breeding. But, to be effective breeders have to go through the testing and then breed according to results.
Even without genetic testing and with very apparent problems both medical and behavioral, this isn't always done.
Doug, DVM
