OFA hip scores and PennHIP distraction index values in dogs

[Saint Mom]

This was posted on another board I'm on and thought it would be of interest to some of you.

Journal of the American Veterinary Medical Association
September 1, 2010, Vol. 237, No. 5, Pages 532-541
doi: 10.2460/javma.237.5.532

Evaluation of the relationship between Orthopedic Foundation for Animals' hip joint scores and PennHIP distraction index values in dogs

Michelle Y. Powers, DVM, DACVS; Georga T. Karbe, Med vet; Thomas P. Gregor, BS; Pamela McKelvie, VMD; William T. N. Culp, VMD, DACVS; Hilary H. Fordyce, VMD; Gail K. Smith, VMD, PhD
Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104. (Powers, Karbe, Gregor, McKelvie, Culp, Fordyce, Smith)
Dr. Powers' present address is Bulger Veterinary Hospital, 247 Chickering Rd, North Andover, MA 01845.

Dr. Culp's present address is the Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616.

Dr. Fordyce's present address is Metropolitan Veterinary Associates, 2626 Van Buren Ave, Norristown, PA 19403.

Presented in abstract form at the Veterinary Orthopedic Society Conference, Val d'Isere, France, March 2000.

Address correspondence to Dr. Smith (smithgk@vet.upenn.edu).
Objective—To compare 2 screening methods for detecting evidence of hip dysplasia (Orthopedic Foundation for Animals [OFA] and PennHIP) in dogs.

Design—Diagnostic test evaluation study.

Animals—439 dogs ≥ 24 months of age that received routine hip joint screening from June 1987 through July 2008.

Procedures—Dogs were sedated, and PennHIP radiography was performed (hip joint– extended [HE], compression, and distraction radiographic views). The HE radiographic view was submitted for OFA evaluation. A copy of the HE radiographic view plus the compression and distraction radiographic views were submitted for routine PennHIP evaluation, including quantification of hip joint laxity via the distraction index (DI).

Results—14% (60/439) of dogs had hip joints scored as excellent by OFA standards; however, 52% (31/60) of those had a DI ≥ 0.30 (range, 0.14 to 0.61). Eighty-two percent of (183/223) dogs with OFA-rated good hip joints had a DI ≥ 0.30 (range, 0.10 to 0.77), and 94% (79/84) of dogs with OFA-rated fair hip joints had a DI ≥ 0.30 (range, 0.14 to 0.77). Of all dogs with fair to excellent hip joints by OFA standards, 80% (293/367) had a DI ≥ 0.30. All dogs with OFA-rated borderline hip joints or mild, moderate, or severe hip dysplasia had a DI ≥ 0.30 (range, 0.30 to 0.83).

Conclusion and Clinical Relevance—Dogs judged as phenotypically normal by the OFA harbored clinically important passive hip joint laxity as determined via distraction radiography. Results suggested that OFA scoring of HE radiographs underestimated susceptibility to osteoarthritis in dogs, which may impede progress in reducing or eliminating hip dysplasia through breeding.


http://avmajournals.avma.org/doi/full/10.2460/javma.237.5.532

[Christinn]

Very interesting.  I got in quite the discussion with my vet who does PennHIP.  He blames OFA for all the problems in people still continuing to breed dogs with hip dysplasia.  He feels like some of those breedings wouldn't have happened had the owner chosen to do a PennHIP rather than OFA x-ray.  I still chose to do OFA with Merlin rather than PennHIP and he was not happy with me...lol!!

[NordicWhispers]

I believe the likelihood of eliminating hip dysplasia is pretty slim with either technique.  It is a polygenic trait influinced by many genes, which is then further influinced by many factors....

From the Canine Inherited Disorders Database..

Polygenic traits are controlled by an unknown number of genes. The gene expression is influenced by a variety of factors including gender, nutrition, breed, rate of growth, and amount of exercise. These traits are quantitative traits - that is, there is a wide range within the population. Such traits include height, weight, character, working abilities, and some genetic defects. Heritability varies within different breeds and within different populations of a particular breed.

Because it is virtually impossible to determine the exact genotype for such traits, it is difficult to control defects with a polygenic mode of inheritance. The best attempts at control are based on a grading scheme for identification of the defect and a breed policy of recording and publishing the results for as many dogs as possible. Canine hip dysplasia is a polygenic trait that remains a problem in most large breeds of dog, despite efforts to control this condition dating back to the 1960s. Breed organizations and veterinarians in various countries have developed control programmes that rely on radiographic evaluation and a central registry of dogs. Thoughtful selection by breeders, using this information, has greatly reduced the incidence of hip dysplasia in those breeds in particular countries.

Grading is the key and has helped reduce the instances but given the mode of inherritance, elimination is virtually impossible.

I've discussed both options with my Reproductive specialist and she is comfortable  staying with OFA.  It will be interesting to see how the breeding community embraces Penn Hipp.

Very interesting article.  I appreciate the post.

[eskieagilitygal]

Very interesting...thanks.

Unfortunately Eskie Breeders as a group do not do enough testing in this area.  Both PenHIP and OFA are not cheap, with OFA currently being the most affordable.

I currently OFA, as the Eskie Breeders who do test within my Mini lines are  using OFA and there is starting to be a decent data base of dogs showing up on it with historical information. Which ever one (PenHIP or OFA) we use I think it's important that Breeders as a group use the same criteria to test,so we can build a good database of the results.  Having our efforts scattered between two rating programs does not benefit us  as fully, as if we were all united in using one program.

As of right now the dogs showing on the OFA data base are mainly the ones who we have kept to breed and or trial in a performance event, such as Agility.  That's a start for sure and does help the breeder  make good decisions about pairing etc, but it would be great to start seeing entire litter results. To be able to see the true picture of what happened in a breeding/pairing.

I have been giving this a lot of thought about any future litters I have, to offer incentives to Companion Homes to have their dogs OFA'd when they turn 2.  It would be expensive, but with Mini's having small litters and with me only planning to breed once every several years it may be doable to help give future Breeders a better picture of what is happening within their lines.

Helene has offered and agreed to OFA Kooza when he turns 2, so I'll be very interested to see how his results turn out and get him in the OFA database.

[nevada.the.eskie]

When I had Nukaq's OFA's done, I spoke to my vet about whether PennHIP or OFA would be best. We came to the conclusion that PennHIP was not worth the money. It would have cost me 3 times as much to go with PennHIP.

Apparently there is a Golden-doodle "breeder" in my area that uses my vet and does both OFA and PennHIP testing. Of the 6 dogs she had tested, 1 had better PennHIP than OFA results, 2 had approximately equal results, and 3 had better OFA than PennHIP results. *NOTE: My vet did not comprimise confidentiality...they just informed me that some of the results were better than other, not what the actual results were, so they could have been talking about Good vs Excellent ratings or Borderline vs Poor.

I also found out that not many vets are willing to go through the process to become certified for PennHIP as it is VERY expensive. Only one of the vets in the office I go to has the certification and he is semi-retired. He only comes in to do the PennHIP x-rays. A tech cannot do them like they can for OFA. Last I knew, none of the other vets were interested in becoming PennHIP certified as the clinic will not pay for it (I guess it runs something like $4000+ and they have to go to Pennsylvania to take one of the tests).

[eskilady]

I have found that alot of mini eskie breeders don't do either - I think they feel that dysplasia is a "big dog" disease so why spend the money to test minis.  I disagree tho as Mona has one hip that is mildly dysplastic.  I am very interested in the hips of the boys that I breed Mona to.

[Saint Mom]

But knowing hip dyspasia is mostly a genetic problem, why would you breed Mona, even if mild when it is recommended not to do it? Isn't it making the wheel turning and not going towards eliminating the problem as much as possible? Not a judgement here Carol. Just trying to sort this thing as we often say we should not breed a dog that has genetic issues.

[101eskies]

We chose to breed Mona because we owed her breeder a puppy and her breeder is one of those that do not believe that this is a problem. Plus, Mona is a nice little mini and has many other great qualities. We do not have a big enough program to simply eliminate a dog based on a small issue, we just breed forward in the best possible way. And since breeding two dogs with excellent hips can still produce a dysplatic dog, we are all just doing the best we can with this issue. My big girl, Madayja, has severe dysplasia. She was not bred. That was not a one we were willing to gamble on.

Plus, our vet says that when only one hip is affected it is usually the result of a mild injury in the past. True dysplasia affects both hips.

[Saint Mom]

Thank you for the explanation.