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As I understand it, hip dysplasia, Eye problems, and now CNM are genetic defects. Many people are breeding their registered retriever to the "good hunter down the road" getting good hunting dogs with no regards to potential genetic defects. Now on to my question, If they are in fact genetic, 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??
 

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Over a couple of generations, wouldn't this take care of the problem in registered dogs??
1. Almost. Hips can be damaged through injury and too much use at a young age (like dock jumping a 1 year old, etc).
2. CNM is a recessive allele. A carrier doesn't produce affected dogs; it takes two carriers to produce affected dogs. Some of the most prominent field producers in history have been carriers. If your dog's pedigree has Candlewoods Super Tanker, Candlewoods Tanks A Lot, or Storm's Riptide Star (all national champions), your dog could be a CNM carrier. That's an awful lot of field trial dogs that never would have existed if your plan were to take place. You can always eliminate the possibilty of having affected pups by breeding only to non-carriers.
why hasn't an organization like AKC taken a position and not allow the registration of pups/dogs unless they have passed a test.
AKC is in the business of making money, and they want to be as profitable as possible. Requiring stringent tests would be nice, but definitely not profitable.
 

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Very good response there Birddogger!
 

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BirdDogger said:
Over a couple of generations, wouldn't this take care of the problem in registered dogs??
1. Almost. Hips can be damaged through injury and too much use at a young age (like dock jumping a 1 year old, etc).
2. CNM is a recessive allele. A carrier doesn't produce affected dogs; it takes two carriers to produce affected dogs. Some of the most prominent field producers in history have been carriers. If your dog's pedigree has Candlewoods Super Tanker, Candlewoods Tanks A Lot, or Storm's Riptide Star (all national champions), your dog could be a CNM carrier. That's an awful lot of field trial dogs that never would have existed if your plan were to take place. You can always eliminate the possibility of having affected pups by breeding only to non-carriers.
why hasn't an organization like AKC taken a position and not allow the registration of pups/dogs unless they have passed a test.
AKC is in the business of making money, and they want to be as profitable as possible. Requiring stringent tests would be nice, but definitely not profitable.
Had those dogs or others that were carriers NOT been able to compete there would have other non carrier dogs winning those Nationals and assuming the Favorite Sire/Dam role in their sted.

IMHO the Breeds field line would have been genetically healthier as a result, and there is no reason to think that the Breeds field prowess would have been hurt for the effort.

john
 

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greta said:
As I understand it, hip dysplasia, Eye problems, and now CNM are genetic defects. Many people are breeding their registered retriever to the "good hunter down the road" getting good hunting dogs with no regards to potential genetic defects. Now on to my question, If they are in fact genetic, 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??
For the same reason that AKC had proposed registering animals at Petland retail outlets. The business of registration not certification...
Education of the buying public and reputable breeders are more effective...
 

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Had those dogs or others that were carriers NOT been able to compete there would have other non carrier dogs winning those Nationals and assuming the Favorite Sire/Dam role in their sted.

IMHO the Breeds field line would have been genetically healthier as a result, and there is no reason to think that the Breeds field prowess would have been hurt for the effort.
I see your point, John, and I agree to some extent. I'll admit to bias because my best buddy is a Super Tanker grandson. The breed's field prowess will continue because of dedicated breeders and trainers like some of those on this forum. That being said, I don't think it can be argued that having Lottie in your dog's bitch line hampers its field prowess in any way :wink: . As buyers, we just have to purchase dogs from tested parents. When all potential buyers demand healthy products, breeders have no choice but to comply.

Out of curiosity: How many people would turn down a chance at pup out of Lottie by a lab that was a non-carrier, like from one of her Abe breedings? There would be no possibility of affected pups, only potential carriers. If your dog were a carrier, you could always have him/her spayed or neutered. Would anyone really refuse a pup from this litter?
 

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BirdDogger said:
As buyers, we just have to purchase dogs from tested parents. When all potential buyers demand healthy products, breeders have no choice but to comply.
OFA has been available for nearly 50 years but how many litters still aren't done? CNM only since around 2000 how many still to be checked? Eyes since the 80's but still aren't done for most litters. So as you say until buyers request these clearances routinely.

I won't buy if they don't advertise testing, but then we will be hit by another recessive that has been hidden for generations.
 

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Is it not up to the breed clubs to suggest required health clearances before breeding? I was under the impression other breeds registered by the AKC have such? Am I incorrect in this assumption?
 

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greta said:
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.

In summary:

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.

Amy Dahl
 

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I don't think you can blame just "the good hunter down the road" for passing on defects.When I was looking for my dog the CNM test was just coming out.I had already decided what lines interested me but
kept hearing different things from different breeders about suspected carriers.A breeder wasn't going to tell me CNM was in his dogs unless somebody proved it.It was a gamble.I already had a deposit down on a litter that was somewhere along those "suspect" lines.I asked the breeder if he would test his dog and he wouldn't.I even offered to help with the cost.The breeder of the stud wouldn't test either. I walked away from that litter and my deposit and narrowed the search to dogs off the white list still along those lines.The sire was off the white list but the dam wasn't.My only gamble (as far as just CNM) was being a carrier at worst.I could live with that.My dog has tested CNM clear but could maybe still have EIC or a zillion other defects that I don't know yet.Knock on wood.I think it is the buyers job to look for the health clearances he wants in a sire and a dam.You can't always trust the breeder.If you could,we wouldn't have Labradoodles and Silver Labs.
 

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Amy,
Excellent post. Thank you for finding a way to paint the total picture. I fear more everyday that if we keep coming up with a new test to add to the already long list of tests that a dog may pass to breed, then we will get to a point where we are harming the breed, not helping it. I won't argue with science, but you can only mess with Mother Nature so much before she teaches you a lesson. :wink:
 

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Illinois Bob said:
I had already decided what lines interested me but
kept hearing different things from different breeders about suspected carriers.A breeder wasn't going to tell me CNM was in his dogs unless somebody proved it.It was a gamble.I already had a deposit down on a litter that was somewhere along those "suspect" lines.I asked the breeder if he would test his dog and he wouldn't.I even offered to help with the cost.The breeder of the stud wouldn't test either.
There's a connection here with the original post. People have a tremendous amount of time, maybe generations of breeding, money, pride, the pain of many washouts along the way, and love (as in "labor of love") invested in their good dogs. They don't want to suddenly buy in to a lottery that has a chance of getting their dog blacklisted.

If breeders and buyers alike recognize that with the test, "carriers" can potentially contribute a great deal to the breed and affecteds can be prevented with certainty, the incentive will exist for breeders and stud owners to test.

Otherwise, we'll probably get there in the end. People will start testing their bitch puppies--before investing their all in them--knowing they can safely breed their "clear" bitch to any stud. They may test entire litters to make sure their keepers are clear, along the way learning what the stud dog is throwing.

I found this on the OptiGen website (they offer the marker test for PRA):

note: Pattern A is "clear"; Pattern B is a probable carrier; Pattern C is a probable affected.

OptiGen said:
Find out everything you can about your dog--then breed or don't breed according to the absence or presence of traits and health considerations you have no control over. Don't let the traits you can control dictate your breeding decisions. You now have control over prcd-PRA. An OptiGen-tested Pattern B or C dog can be bred to a Pattern A dog without producing affected offspring. B pups can be bred again to As. This is how you eliminate the defective gene from your line. Your C dog's progeny will all be Bs.
There is a risk of a "witch hunt," which will only harm the breed.

Amy Dahl
 
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