EAP I think you are very naive to think that all registered pedigree breeders actually care about hte conditions their dogs inherit?
i am very aware of the unscrupulous nature of the dog breeding business. Breed clubs / the KC place minimal standards on members. X-breeders don't even have those (scant) limitations.
if a dog has a pedigree - you can see whether its father is also its grandfather, and great-grandfather, or if it is the product of a brother-sister mating, the age of the brood bitch is noted etc. a dog with no pedigree at all comes without even that basic level of paperwork.
common pratice amongst those breeding in puppy farms is to inbreed to such an extent the dog is its own grandfather - and ruin the health of the dog by weaning it early, feeding it inadequately, keeping in cold pest-ridden conditions -
although this happens to both x-breeds and pedigree dogs, a pedigree breeder will not keep any kind of good reputation if they are caught doing this, they are more accountable. breeding dogs because you wish to keep one to show, is after all, a much better reason than wanting to earn some extra money from selling the litter.
actualy, thinking about that article linked to made me rather sad..cos most of the things we see the vet for are accidents..slit pads, broken bones, cuts..if the difference in vetinary attention is that great, there must be many x-breed dogs around with broken bones that never received even the most basic treatment. All because the financial value of the dog is lower, an it would cost less to get another one.