a) What are the pros and cons of OFA vs. Penn Hip hip evaluations?
b) I have some Pyrenees whose hips were evaluated using OFA. I am changing to PennHIP. I would like to compare my OFA scores to my PennHIP scores. What is the scale to compare PennHIP to OFA? An OFA Excellent is equivalent to a PennHIP score of__________. An OFA Good is equivalent to a PennHIP score of__________. An OFA Fair is equivalent to PennHIP of___________. OFA poor is equivalent to a PennHIP score of____________.
Not eligible for an OFA because the score was too poor to qualify is equivalent to PennHIP score of___________. Please fill in the blanks.
Answered by: James L. Cook, DVM, PhD, DACVS, DACVSMR:
a) OFA pros = amount of data it is based on and positive effects on decreasing CHD by using registry correctly, accuracy at 2 years of age.
OFA cons = subjective grading, not final until 2 years of age (too late to prevent, many already bred)
PennHIP pros = objective measurement (DI), done early in life, good evidence for effectiveness if DI>0.7 or <0.4
PennHIP cons = not nearly as much data as OFA, the 0.4-0.7 “grey zone”, costs and requirements to get “certified"
b) Unfortunately, there is no valid data to directly answer this question/fill in the blanks. The PennHIP scores vary among breeds and age to some degree. But, the thing that can be said in general to address this as well as possible is that PennHIP DI > 0.7 measured during development is very likely to be associated with hip dysplasia and secondary osteoarthritis (OFA = mild, moderate or severe) when the dog is 2 years of age and PennHIP DI < 0.4 measured during development is very likely to be associated with OFA = fair, good or excellent when the dog is 2 years of age. Unfortunately, DI = 0.4-0.7 is a “grey zone”, i.e. OFA = borderline.
