
Of course - in an ideal world only the best should be bred to the best. In my own breed, where gonioscopy is the main test done under the BVA/KC scheme, it's either a fail or pass and a fail result is noted on the Registration papers of any progeny. This worries me to some extent as the test only shows a pre-disposition to eventual glaucoma, not that it WILL happen. I've known some really good dogs be lost to the gene pool -throwing the baby out with the bathwater. Not so with Hip and Elbow scores (or are they so noted?), which of course, can and is also done with my breed, but not so often. But as long as we live in a 'free world' it's going to be impossible to dictate which dogs should be bred from, and which shouldn't be. We can only educate the buying public and I suppose, less caring breeders!
And never forget that with displasia, environment/rearing does play a part although not as big a part as genetics.