Being new to dog-ownership-in-general and owning-goldens-in-particular, I am fairly interested in OFA and PennHIP as it relates to anticipating health concerns with our puppy/dog. And, seeing as it's been a while since this topic was directly addressed on a GRF thread, it seemed like an appropriate time to "stir the pot". 😁
The following table is something I put together, using information from a slightly dated study (but, the only study I found that wasn't on a site that seemed like it might be biased). This study addressed 439 dogs, aged 2-or-older, that were assessed from June '87 to July '08.
![875436]( "875436")
Based on my readings on the OFA site, a rating of "Excellent", "Good", or "Fair" is considered "passing". My assumption is that any other rating is considered "failed".
Based on my readings on PennHIP, the "magic number" for the diffraction index (DI) is 0.30. DI's above 0.30 are supposed to indicate an increased risk of hip issues. While I have not seen anything that explicitly correlates at PennHIP DI of 0.30 with an OFA rating of "Fair", most of the information I have found online seems to infer this association.
What I found interesting is that the OFA assessments indicated 84% of the dogs assessed were cleared for hips. The study used the inferred association of a DI of 0.30 to an OFA "Fair" as the line-in-the-sand, with significant numbers of the OFA-certified dogs not meeting the PennHIP metric. I then adjusted the numbers to reflect only those dogs that both met minimum OFA and PennHIP ratings. This resulted in a 5x increase in the numbers of dogs that would not be recommended for breeding.
Since I am not a breeder, this information is less of a concern, although these values greatly increase my interest in seeing how our Kona scores (for purposes of planning for health, and maybe preventative measures if warranted). But, if I were a breeder, I think I'd be concerned about the potential impact of such a significant decrease in the potential pool of dogs for breeding.
Thoughts?
The following table is something I put together, using information from a slightly dated study (but, the only study I found that wasn't on a site that seemed like it might be biased). This study addressed 439 dogs, aged 2-or-older, that were assessed from June '87 to July '08.
Based on my readings on the OFA site, a rating of "Excellent", "Good", or "Fair" is considered "passing". My assumption is that any other rating is considered "failed".
Based on my readings on PennHIP, the "magic number" for the diffraction index (DI) is 0.30. DI's above 0.30 are supposed to indicate an increased risk of hip issues. While I have not seen anything that explicitly correlates at PennHIP DI of 0.30 with an OFA rating of "Fair", most of the information I have found online seems to infer this association.
What I found interesting is that the OFA assessments indicated 84% of the dogs assessed were cleared for hips. The study used the inferred association of a DI of 0.30 to an OFA "Fair" as the line-in-the-sand, with significant numbers of the OFA-certified dogs not meeting the PennHIP metric. I then adjusted the numbers to reflect only those dogs that both met minimum OFA and PennHIP ratings. This resulted in a 5x increase in the numbers of dogs that would not be recommended for breeding.
Since I am not a breeder, this information is less of a concern, although these values greatly increase my interest in seeing how our Kona scores (for purposes of planning for health, and maybe preventative measures if warranted). But, if I were a breeder, I think I'd be concerned about the potential impact of such a significant decrease in the potential pool of dogs for breeding.
Thoughts?
I think DI is a good, if slightly arbitrary value that could improve breeding programs, however at the cost of decreasing an already small gene pool. 
