When we were ready to add a Sheltie to our family, I made sure prospective breeders met a long check list of requirements from socialization to genetic testing. Since Shelties are prone to hip dysplasia, I only considered breeders who screened the parents’ hips. The standard screening model is the Orthopedic Foundation for Animals test , or more commonly known as the OFA.
So I was shocked to find out that the OFA test may not predict hip dysplasia risk as acurantly as once thought. A new study published in the Journal of the American Veterinary Medical Association  found that the OFA test may be underestimating hip dysplasia and osteoarthritis susceptibility in canines. The research compared the standard OFA test and the University of Pennsivania’s PennHIP screening model with 439 dogs older than two years. They found that 80 percent of dogs judged to be normal by the OFA test would be flagged to be at risk of developing osteoarthritis and hip dysplasia by the PennHIP test.
Furthermore, according to UPenn researchers, even if breeders were to selectively breed only those dogs having OFA-rated "excellent" hips -- the highest ranking -- the study suggests that 52 to 100 percent of offspring, depending on the breed, would be susceptible to hip dysplasia based on the PennHIP test.
Before making any conclusions, I’d like to see an independent study compare the two tests (University of Pennsylvania ran the study on their own screening method, funded by the University, the National Institutes of Health, The Seeing Eye Inc., the Morris Animal Foundation, and Nestle Purina Co.), as well as a long term study. However, if it’s true, the results are alarming considering how many breeders rely on the OFA test to make lineage decisions.