One canine disease most folks are familiar with is dysplasia. It’s a nasty disease that wears away the joint and eventually causes pain, reduced mobility and can lead to major surgery.
It’s not easy to pin down the cause. Genetics, diet, environment, activity level all play a part. And sometimes even when both parents have great hip joints, a pup can develop it.
While getting tests on ALL pups would be ideal in order to get the best picture possible of the inheritability of hip dysplasia, the cost and ability to get new owners to agree to this is daunting. So most reputable breeders rely on testing the only the parents.
There are a few ways to do the evaluation. All would require an xray.
Have your vet complete an xray and give you an opinion on whether there is any dysplasia evident. I imagine most all vets would give their honest opinion, good bad or indifferent, but if they aren’t a board certified orthopedic vet, their opinion would carry less weight. I don’t know any reputable breeders using this method.
Have your vet send the film to the OFA (Orthopedic Foundation for Animals) where for an additional fee, 3 orthopedic vets will do an evalution and give it a rating of Excellent, Good, Fair, Borderline, Mild, Moderate, Severe.
Inter-rater reliability of the orthopedic vets has been sited at about 95%, which is pretty darn good. Generally, what is being evaluated in the xray is how well the ball and socket fit together and if there is any wearing away of the bone or other bony abnormalities.
Anything less than Fair is generally considered unacceptable for breeding. Personally, I think that is being overly generous considering the lack of progress made over the years to reduce hip dysplasia in dogs. I wouldn’t breed anything less than a Good rating.
Most reputable breeders use OFA for screening to determine if there is dysplasia. A preliminary test can be done before two years of age, but a final evaluation should be done after the pup reaches two.
More interesting to me was looking at a graph for Shetland Sheepdogs' OFA scores over the course of several decades. There was essentially substantial increase in the number of “Excellent” scores over the course of decades.
This says to me that we were not doing anything helpful with this xray. And while it might feel good to get an “Excellent” rating for your Shetland Sheepdog, if it won't help you choose the right specimen to breed for improvement in the future generations, what’s the point?
I prefer to use the PennHip xray method for evaluations rather than the Orthopedic Foundation for Animals x-ray.