Woofgang, i thank you for your reasoned arguments and will give some thoughts on this. Sadly many people make generalised comments such as those about GSD's having roach backs and Bulldogs not being able to whelp normally etc. However, if people buying puppies were to insist that the parents of their puppy had normal conformation and in the case of Bulldogs were self whelping this would help to eradicate the faults. I have a GSD puppy booked whose parents have had all health tests, and both have correct toplines without a roach back and both have firm sound hocks. The case of CLAD in irish Setters is one where the KC will no longer register puppies unless both parents are clear, as they now have a DNA test which has been around for over five years. The GSD people are at present trying to get the KC to agree to health testing before registering puppies, and before allowing them to be shown, but the KC will not make it a requirement. The KC have stopped registering puppies from very close parents, such as brother/sister, mother/son, father/daughter, which in my opinion will make very little difference as unless the parents have a problem the offspring won't have. Two completely unrelated dogs could both have the same problem and produce puppies with it. I had an accidental mother/son mating and the 'pups' from that litter will be fourteen in August, and all are still alive and well. My oldest bitch is fourteen and a half and still winning in the show ring. As for Terriers being picked up by their tails, when they were docked this was so the handlers had something to get hold of when removing them from rabbit holes etc.
There is no evidence to suggest that crossbreeds are any more healthy than pedigrees this is an urban myth. If you mate two unhealthy dogs of different breeds they will produce unhealthy puppies. And as for rescue dogs, why are there so many crossbreeds in rescue kennels?