We ought to recognize that MVD is pervasive in the CKCS, and it will remain so, much like Chiari-like Malformation. We cannot get rid of MVD without getting rid of the breed.
Early-onset (a murmur by the fifth birthday) MVD should be a different matter. That can be eliminated in as few as two or three future generations, if breeders would follow the MVD breeding protocol. Nearly all breeders don't, of course, so early-onset MVD remains a 50-50 chance for each dog produced.
I was reading on another CKCS-List today about this Cavalier breeder in Oklahoma who proudly claims that breeders health test and agonize over decisions, and that her cardiologist thinks progress is being made, and she really doesn't know how much more they can do, and so on.
Well, her breeder friends don't follow the protocol. Some of them may test their stocks' hearts, and some of those may not use stock which come up with murmurs, but they still breed underaged (under 2.5 years) Cavaliers, and the fact remains that an underaged Cavalier with a clear heart is just an underaged Cavalier that ought not be bred yet.
Perhaps the age of onset is being pushed back a little bit among those breeders who really do test and then only breed the (underaged) ones which pass. But when you consider that the MVD protocol was introduced eleven years ago in the US, if all breeders began following it then, they would have produced three to four generations of Cavaliers since then, and the end result could have been that early-onset MVD would have been eliminated by now.
Then this Oklahoma breeder attacks a Connecticut CKCS breeder (one, I must say, who has vast more CKCS breeding experience, health testing experience, and winning-in-the-ring experience than the Oklahoma lady, and who does in fact follow the MVD breeding protocol) for daring to state facts about some cardiologists not feeling that any progress is being made.
The Oklahoma lady's bottom line is that Cavalier people should control the dissemination of negative commentary about the breed. So, that is the typical US Cavalier breeder's solution to the early-onset MVD problem: Don't disclose any of the bad news, and then everything will be all right!