What are the benefits of OFA vs PennHips?

In my opinion PennHIP is better, although of course there are people who will disagree and give good reasons as well.

TLDR: read the two websites, and then go through the various studies that PennHIP links too. Very interesting. Not sure if OFA lists studies too. PennHIP is better cause it's trained, OFA is cheaper and older.

Vet who take x-rays for PennHIP are actually trained in how to position the dog for the x-rays. Any vet, trained or not, can take the x-rays for OFA. Improper positioning can result in a poor rating when in fact the hips are good, or vice versa. Once a vet completes a PennHIP workshop, they then must send sets of x-rays of different dogs to PennHIP, and PennHIP will evaluate whether the x-rays were done properly. These cannot be marketed as *proper* x-rays as the vet is not yet certified. Once the vet has sent in 5 sets of x-rays that are approved of, then the vet gets the certification to do x-rays for Pennhip, professionally.

The vet takes 3 x-rays, one is the OFA position, and a copy of that can be sent to OFA. That way, your dog can be certified with both OFA and PennHIP.

Once the x-rays are sent in, specialist veterinarians at OFA or PennHIP look at them and evaluate them. At OFA, the evaluations are qualitative, which means that the vet looks at them and says "they look good" or "they look bad".

"Radiographs of animals...are independently evaluated by three randomly selected, board-certified veterinary radiologists from a pool of 20 to 25 consulting radiologists..."

There are 7 ratings that a dog can get. Excellent, good, fair, borderline, mild, moderate, and severe. The "grades of excellent, good and fair are within normal limits and are given OFA numbers". "Radiographs of borderline, mild, moderate and severely dysplastic hip grades are reviewed by the OFA radiologist and a radiographic report is generated documenting the abnormal radiographic findings."

http://www.offa.org/hd_info.html

http://www.offa.org/hd_procedures.html

What this means, is that set of vets could evaluate a dog's hips as excellent, and with another dog a different set could give it a good or fair rating, even if the second dog's hips were better than the first. This is because it is qualitative.

PennHIP tests for hip laxity, which is a very good predictor of whether a dog will develop HD and CHD. It is a quantitative testing, so no matter what vet is looking at the x-rays, they will be giving the same rating. They are also rated on what the actual condition of the hip is in. Here is a sample report. The thing about PennHIP that some people don't like, is they simply say whether there is any sign of HD or not. It's yes or no.

http://research.vet.upenn.edu/pennhip/PennHIPMetho...

So, if you want to know the most about your dog, you may want to send to both. IMO, if you use the PennHIP, you're more likely to breed HD out of dogs. This is the method that was used for the Seeing Eye dogs, and the percentage of HD in that population of GSDs is much lower as a whole than the outside population.