I think breeders should be doing some sort of dog sport with their dogs be that showing, agility, obedience, endurance etc ( Some folk have retired from some of these sports after many many years in I would include them in there as people I would buy from as well)
Health testing is a must but just like humans there are no guarantees as the amount of gene combinations that can happen.
All breeders should be doing DNA testing for Curly Coat/Dry Eye and Episodic Falling and breeding can be done with a carrier as long as not to another carrier ( well I would never mate a carrier to a carrier)
MVD has no DNA test, all breeders should be getting their breeding dogs and those who have been a part of their breeding programme heart tested by cardiologist and there are heart clinics in most states at least once a year.
All breeds have some health issues sadly just a matter of doing the best you can by choosing a breeder who is there for the breed, doesnt necessarily mean the most ribbons or awards but those who have the breed at heart