Some breeders say they test for genetic problems before breeding but dont show proof. This site you can look up for your self if the pups parents have in fact had the testing done and verify it.
All you have to do is type in the registered names of your dogs parents and see if they've been tested. I thought it was cool. And could be helpful when looking for a breeder that breeds with healthy puppies in mind too.
http://www.offa.org/index.html