How are OFA rating supposed to be used?
A. To properly use the OFA ratings, the breeder must know the OFA ratings for the Sire and Dam, for ALL of the siblings of both the Sire and Dam, for All four Grandparents, and ALL of the Grandparents’ siblings, for ALL eight Great-grandparents and for ALL of the Great-grandparents’ siblings. These OFA ratings must then be placed in a “vertical pedigree” and calculated to determine whether or not a dog should be bred. Assuming that each animal is only bred once and each litter has 10 pups, that is a minimum of 140 dogs with OFA ratings that the breeder must have recorded. What is important is that the mass quantity of dogs in that list be free of Hip Dysplasia. Since Hip Dysplasia has both an nutritional and complex genetic components, it is very possible to have a dog with excellent hips whose entire genetic makeup is composed of dogs with horrible hips(and such a dog will throw pups with bad hips). Its for that reason that any individual dog’s OFA rating is a worthless predictor of H
