why hasn't an organization like AKC taken a position and not allow the registration of pups/dogs unless they have passed a test. Give a dog a limited registration until they have passed a a CERF exam, received a good or excellent on a hip exam and negative for CNM then offer a full registration. Over a couple of generations, wouldn't this take care of the problem in registered dogs??
Many reasons. The AKC's job is to register dogs. Defining the breed standard is up to the breed clubs, and interpreting it in trying to select for "quality" is up to the judgment and skill of breeders.
Trying to breed good dogs means selective
breeding. Any breeder is limited in how selective he or she can be. One person can only raise, train, and try out so many bitches, and there are limitations on how many stud dogs one can get to know thoroughly as well. There are many important aspects to a working retriever, including temperament, coat, conformation, desire, eyesight, nose, hearing, intelligence, trainability, watergoing, other health issues, etc. The more intensely you select for (or against) one trait, the less you are able to select for others.
Deciding ahead of time to rule out dogs below a certain grade on a particular trait is called an "absolute culling standard." That is what the OP is advocating. This leaves no room to select for the exceptional individual if his one weak area is in one of the absolutes.
To select against a trait effectively, it helps to know the inheritance of the trait. Hip dysplasia, for example, is polygenic. The experts tell us that "pedigree breadth" is more important than individual phenotype. In other words, you will get better hips breeding from a "Fair" all of whose siblings passed OFA than from an "Excellent" who had siblings fail (assuming comparable numbers of sibs, etc.). So the "good or excellent" criterion is not effective at breeding for good hips, much less good dogs overall.
I question the emphasis given to selecting for hips. I had a dog who went lame at 12. I had an x-ray submitted to an orthopedist, who wrote, "this may be the worst case of hip dysplasia I've seen in 30 years of clinical practice." At the end of my dog's life, I felt the drugs we used for pain and inflammation hastened the heart trouble that ultimately killed him. Not good; but there are much worse things. Huge numbers of dogs have been washed out for failing OFA, and we've still got hip dysplasia. The increasing sophistication of breeders and their vets in pre-screening x-rays confounds any measure of progress made; certainly there are still dysplastic dogs out of the "best" hip pedigrees. That's a heck of a lot of selectivity sacrificed: for what?
Regarding CERF. Selecting against dogs affected with entropion or any recessive condition will have very little effect on the incidence in the general population. With recessives, the rarer they get, the less effective selection against affected animals becomes.
When a recessive can be identified with a DNA test, like PRA, then it becomes instantly possible to avoid ever producing an affected dog. It is in principle possible to eliminate the allele from the population in a single generation, but the geneticists (for example Dr. Jerrold Bell of Tufts University) advise, instead, judiciously using identified "carriers" of exceptional quality and selecting so as to reduce the incidence of carriers in each generation.
I would expect the same recommendation to apply in the case of CNM.
There is another reason to avoid absolute culling standards for defects. Every dog is thought to carry some genetic defects--I think the number is six or eight on average. Some of these are so rare that two carriers are almost never bred together, and the conditions may never have been identified as a result. Others are more subtle--minor metabolic defects, perhaps, that make a dog a "hard keeper" or maybe prone to early breakdown. When you practice absolute culling for some trait, and consequently narrow the gene pool, it is probable that you increase the incidence of some other, less- or unknown disorder. The same can occur when a stud dog is wildly popular and many of his offspring are high quality and are used in breeding. I expect OFA and popular sires are the reasons we are seeing EIC today.
You can think of it as visible and invisible defects. Intensive selection against visible defects increases the invisible defects.
Absolute culling standards may have low or no effectiveness at reducing the incidence of a problem;
Absolute culling standards necessarily involve sacrificing selectivity, both for
desirable traits and against
other undesirable traits; and
Absolute culling standards probably (statistically) increase the incidence of as-yet-uncharacterized defects.
In my opinion it is appropriate for buyers to educate themselves, and ask breeders what their priorities are and what health screenings the sire and dam (and other relatives) have passed. Also in my opinion it is desirable to leave it to the discretion of breeders which dogs they will select for breeding. Opinions differ among breeders--but we never know which of us will "paint ourselves into a corner" in our breeding program, and need an outcross to the dogs of someone who made opposite choices to save us.
Please keep in mind the legislative climate, involving an immense, nationwide push to get governments (city, state, and federal) involved in regulating dog breeding and taking decisions out of the hands of breeders. And, of course, squeezing many breeders between state laws and local ordinances so they are forced to go out of business.