Rosehall Kennel uses OFA testing for both hips and elbows for our breeding dogs in our efforts to minimize the risks of hip and elbow dysplasia in our puppies. Some dog breeds exhibit a strong genetic correlation between hip and elbow ratings of the parents and that of the pups. Our experience with German Shepherds is that although it is undeniable that there is genetic link, it doesn't seem as strong in GSDs as in some other breeds. We have purchased potential breeding dogs that had both parents OFA rated excellent and have had to place the pup in a pet home because it would not OFA certify. We also know of a pup that had both parents rated mild dysplastic and the pup rated OFA excellent. We do see strong evidence (as also stated on OFA's web site) that the background for several generations is very important in reducing the likelihood of dysplasia in the pups. Therefore we not only test our breeding dogs with OFA, we are cautious about choosing our out cross breeding dogs and look for strong OFA ratings in their pedigrees. Here are links to a couple of Wikipedia articles about hip and elbow dysplasia in dogs:
(From OFA's web site:)
Can environment or food cause hip dysplasia?
No, hip dysplasia is a multiple gene, inherited disease. Environmental factors, like high caloric diet during the rapid growth phase, may exacerbate changes in dysplastic hips but will not create hip dysplasia. There also is no evidence in the scientific literature that supplements (i.e Vitamin C) will prevent hip dysplasia. Reduced caloric intake and glucosamine products in immature animals genetically predisposed for hip dysplasia may lessen the pathologic changes associated with hip dysplasia.
http://www.offa.org/hd_info.html hip dysplasia information
http://www.offa.org/ed_faqs.html elbow dysplasia information
http://www.offa.org/hd_guidelines.html OFA's recommended breeding guidelines regarding hip dysplasia
http://www.offa.org/hd_grades.html explanation of OFA's hip grading system