Notes on OFA / PennHip Testing
Getting a life-long companion can be a very overwhelming process. We all want our four-legged family to be happy and healthy. Determining which factors lead to healthier dogs in the long-term can be a difficult to figure out. A popular website for selling health screened dogs has pushed the idea that OFA and PennHip testing for Golden Retrievers reduces the risk of getting a puppy with potential hip and elbow issues. While this testing could help reduce the risk of hip dysplasia, the full story is more complicated.
The AKC notes that “Hip dysplasia is a polygenic, multifactorial disease” (1). Polygenic traits are common in dogs and are what makes one breed different from another breed. The Institute of Canine Biology describes how these traits have been bred into specific breeds (2). In short, the traits that give us the Golden Retriever are also the traits that make them susceptible to hip dysplasia. Furthermore, selective breeding to limit only dogs with perfect OFA results could result in other polygenic conditions to be discovered down the road.
Keep in mind the same traits that make Golden’s susceptible to hip dysplasia also give us:
Environmental factors play a part in your Golden’s relationship with hip dysplasia (3). Proper nutrition can influence growth rates which can affect the severity of the disease. Exercise and stress put on the joints can impact the development of hip dysplasia. We recommend using puppy food specifically formulated for “Large Breed Puppies”. We have seen a significant difference in controlled growth rates using these food vs regular puppy food.
Because environmental factors can impact the severity of the disease, and OFA PennHip screening is observational and not based on genetic tests, there are tricks breeders use to pass these tests that buyers should be aware of. Screening is much easier to pass when dogs are younger (popular sites like Good Dog allow for preliminary OFA certificates which are done at a very young age), have not had their first heat, have not had puppies (Sage’s PennHip was done after she had 3 litters) and are put on a diet and exercise regiment before testing.
Additionally, dogs that do not initially pass can be retested. Because the tests are subjective, results can vary based on who is reviewing the xrays. There is also variation based on who does the xrays and how the dogs are positioned during xray. Variations also exist between OFA and PennHip testing methods. All these variables raise concerns for us on the weight people put on OFA / PennHip testing when evaluating breeding programs.
We put more focus on testing tied to specific genes and pedigrees to reduce inbreeding. We make sure our puppies do not have genetic markers for Ichthyosis / ICH (common skin condition in Goldens), progressive retinal atrophy, and muscular dystrophy. Some conditions require only one parent to be clear. We make sure both parents are clear of meaningful genetic markers.