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Originally Posted by nrhareiner  First what you are stating is that the dog carries the ressive form of the gene. Which give him a 25% chance of being clear and 50% chance of being a carrier and 25% of being afflicted. If his full sister has it and is experssing it and neither parnet has it then that trate is resessive. SO the female has 2 coppies or is homezygous for the trate. IF your male does not express the trait and it is resessive then he is either clare(25%) or is a carrier(50%). So knowing this even if he is tested clear with an exray he should still not be bred as he can still pass it on to 50% of his get and both parents sould also not be bred as they are carriers. This way you would stop the defect with in a few generations. NOw if there is a genetic test for the defect then this becomes very easy. If they do not carrie it then they can not pass it. You would also know if they are carriers or not. Make breeding desitions easier.
If the trait is a domint trait then if it is not expressed then they can not pass it on period. So once you have a neg animal the next generation would be negative as well no need to test.
As for conformation. If an animal is conformationally correct to do the work requiered then it all is as it sould be and the defect is not genetic then they should hold up under a work load.
Ex. If an animal is not correct in its hocks and are post leged then say asking them to jump, make fast turns and hard stops requiered in many performance events then the animal is going to brack down. IF the dog/animal is put togather correctly they should hold up well under a work load and be able to excell in the work bred to perform.
Heidi |
Heidi, these last 2 sections are not necessarily true....i used to show dogs and it had been brought to my attention quite a few times by other breeders that just b/c the dogs were "formed" correctly did not mean that there were no defects in that animal......i knew of one "breeder" that had champion dogs and found out a few had HD and still bred them (using the certificates of non CH dogs that tested clear; this is part of the reason for the microchipping b/4 cert)......i also have 2 BC's w/ HD and they will go till they "dropped dead" if i let them......a friend has a BC also that has SEVERE HD (her sockets are almost non existant) and most people would never know it......and i have seen dogs work from dawn till dusk w/ problems (even a half blind BC that they had no idea he was till they had his eyes tested) b/c some dogs won't give in to it...... i have called HD on a lot of dogs over the past 10 yrs (including knowing that my male had it when he was 4 mo old) and have been right every time......not many people can do that, including your "top breeders".....so you see, the need to test is imperative......and, yes, you can take 2 parents that test clear and still throw the problem.....somewhere along the line a recessive is going to show up and until everything is done thru DNA test to know who is a carrier/non-afflicted/afflicted these will crop up even more so.....
