Considering how widespread the two main genetic disorders are in this breed (MVD and CM/SM), plus a handful of other fairly common issues (hips, patellas, eyes, etc.), a prospective puppy buyer has her work cut out for her just trying to find a breeder who actually walks-the-walk by not just testing for these disorders, but by also following the breeding protocols designed to try to avoid the disorders in future generations.
There are so few cavalier breeders throughout the world who follow just the two most important protocols -- those of MVD and CM/SM -- that I suspect that most prospective buyers actually will not be successful in finding any breeders who do so, in most countries.
So, what is the buyer to do after an exhaustive, unsuccessful search? As I see it, she has two choices: (1) switch to searching for another breed, or (2) swallow hard and buy a cavalier anyway.
If the buyer decides to buy a cavalier puppy from a breeder who has not followed the protocols essential to reducing the incidence of early-onset MVD and CM/SM, she ought to ask herself why she is willing to do such a thing(?).
Is having a cavalier so important that she is willing to financially encourage a breeder who has not followed the protocols, to continue not following them in the future (thereby creating future generations of puppies which assuredly will suffer from these diseases)?
Is having a cavalier so important that she is willing to assume the financial responsibility of caring for a dog with MVD for most of its likely shortened lifespan? Is she willing to cover the very high costs of MRIs, medications, and possibly surgery for CM/SM?
I think the most important question is: Does the prospective puppy buyer want to be party to encouraging cavalier breeders to continue to create potential basket-cases?