Just wanted to thanks everybody for there help since joining this forum and I have indeed gained plenty of knowledge from reading health tests and ebvs. Having said that having looking at various ebv I am far from convinced of there accuracy. For example we looked at one puppy and checked the sires results for hip test now on the bar graph it gave + 3 worse than bread average. Now from my initial reaction that would have scared me off but on further investigation found his health test going way back to great, great grandparents all were tested and not one dog had a higher hip score than 10 over both hips! So this begs the question of where a + 3 worse than average score comes from. Now looking at the litter this stud dog has produced he has produced over 150 puppies and 3 of these pupppies have very poor hip scores hence I assume the poor ebv reading for the stud dog. Having spoke to different vets the likely hood would seem either very bad luck with the puppies with bad hip score 20+ or poor genes on the bitches side. The point I am making is the stud dogs ebv is poor but actually he might well be a amazing stud dog just and has a great history looking back at pedigree and health tests. Also had a look at a mates labrador today he scores -22 on hips and 65 percent confidence despite only half of the health pediree having ever been tested?? Look forward to hearing other peoples views and experinces
I'm not that knowledgeable on the KC EBV scores but my understanding is that a stud dog's, or bitch's ebv is calculated not just on their own scores but with those of the their littermates, where known; hopefully @JulieT will offer some guidance and explanation as she knows a lot more about the ebv scheme than I do - I didn't have the benefit of such a scheme in France when getting my girl. I just wanted to clarify about the hip scores Is that a score of 10 or less for each hip or when the two scores are added together as it does make a difference?
Hi the stud dog had no higher than ten in both hips so the total score was lower than 10. Also does anyone know how quickly HD can be improved through breading? ie great grandparent to puppy etc?
HD (and lots of other disorders) are 'complex' - it is not straightforward to determine how problems are inherited, and it's not at all clear how disorders are inherited from parents to offspring, so I don't think there is an easy answer to your question. The trend for the Labrador breed as a whole is for an improvement, although I think it is quite slow. You can see improvements over many years - there was an improvement in the mean from 16 to 12 from 1996 to 2006, for example.
The score for each hip is added together to get the overall hip score so for instance if a dog had 7/7 hip scores (one score for right hip and on for left hip) the overall hip score would be 14 which is higher than he breed average of 12. Also to be taken knot consideration is the balance of the scores for instance a score of 6/6 would be better than one of 8/4 although they both add up to the breed average. It is very possible to find parents with 0/0 scores now. I don't know if any one can say for certain how quickly HD can be improved. It is entirely possible for parents with 0/0 scores with grandparents with 0/0 scores to produce a puppy that has HD. Although parents and grandparents may have good hips they could still be carrying the as yet unidentified genes which cause both HD and ED - it's a little like various conditions in humans, colour blandness for example, which suddenly appears because hens have been inherited from both parents. In our dogs the best hip and elbow scores five us confidence that they should be fit and healthy pups with no problems, sadly it's not a guarantee.
