More confusing than helpful so editing
Lush: GCH Am CH Harborview Sweeter Than 'Shine At PoeticGold CGC
Tally: Goldiva Raleigh Tangled Up In Blue CD RAE TDI TT CGC
Copley: BOS Chantilly's Bright Lights Big City RN TDI CGC
Finn: Sand Dancer's Infinite Sky TDI TT CGC
Tango: Topbrass Everlore Talk Of The Town TT CGC(co owned)
They both try to measure the quality of the hip joint, but they use somewhat different measurements and systems for rating those measurements.
OFA rates the hips with an overall qualitative statement: excellent, good, fair, dysplastic. Fair and up means no sign of diseases, but good or excellent is better because it reflects a better shape to the socket and ball joint of the hip. You mail one radiograph of the extended hips to OFA, and three vets examine the image to produce the official rating.
PennHIP uses a quantitative measurement of hip laxity (how loose the joint is) in order to predict disease. It uses three different positions and radiographs (extended, compressed, and distracted). It creates a number called the distraction index that you can use to compare hips in a more specific way than OFA's qualitative ratings. This is slightly oversimplified, but basically, the higher the distraction index, the looser (and more disease prone) the hip. You also get the hips put on a percentile scale against other PennHIPed dogs in the breed, do you know where your dog's DI falls.
Both are considered excellent ways to help breeders reduce hip problems in their breed by ensuring breeding stock is free of disease. OFA is more straightforward and publicly verifiable, and it's currently the gold standard (pun intended) for Golden breeders. Lots of breeders use PennHIP on top by having all the radiographs taken at the same time (one of the three PennHIP x-rays is the same one you'd use for OFA). That way you get a rating from OFA you can post publicly, and also the more specific information from PennHIP that might be helpful for an experienced, knowledgeable breeder who's trying to create impeccable hips for their canine athletes.
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