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OFA or PennHip?

Posted: Sat Mar 10, 2007 12:15 pm
by bondoron
Does anyone think there is an advantage of one over the other?

Posted: Sat Mar 10, 2007 12:25 pm
by Greg Jennings
From the descriptions that I've heard, the PennHip is more thorough. It's results are certainly finer-grained than OFA. The OFA has more recognition in many circles.

Best,

Posted: Sat Mar 10, 2007 4:59 pm
by SwitchGrassWPG
Penn Hip gives you an actual measurement of laxity in the joint where OFA grading could be considered a judgment call on the person reading the film.

All Penn Hip films are submitted for evaluation where (for the most part) only films expected to pass with a fair or better are sent in for formal evaluation.

Jay

Posted: Sat Mar 10, 2007 8:19 pm
by OhioOnPoint
I think OFA is more known. For what it's worth.

Posted: Sat Mar 10, 2007 8:23 pm
by DKRick
Not having dealt with this much I would like to know more?

Penn hip compares dogs that is that just for the current year?

What do you guys feel about a dog with just Good OFA? I think that is the rating I am thinking of were they pass but barely?

How do you guys feel about Penn-Hip being able to be done at such a young age do you think a person is wise to wait till later?

Rick

Posted: Sat Mar 10, 2007 8:44 pm
by snips
A Good rating is fine. Fair is probably what you are referring to as barely passing.

Posted: Sun Mar 11, 2007 12:41 pm
by Windyhills
I'll toss what I've learned and believe into the ring. Not a simple issue.

Both systems require reading of film by a competent person--OFA differs in that many vets handle it in house--with (some say) differing accuracies due to competence issues, whereas Pennhip film is all sent in to very experienced people for reading.

Penhip requires all dog films to be sent in--that's optional for OFA. If your dog ends up with lousy hips, you don't have to report that to OFA. Of course, OFA won't give you any rating either.

I believe Pennhip requires all dogs to be knocked out with anesthesia, but could be wrong about that. I know that they measure laxity of the joint which requires some major jerking around of bones and joints--not something you want to witness on your dog, I've been told--whereas OFA can be handled with a dog that can be controlled without anesthesia. That might be a concern for some who know that anesthesia in pets is a bit more dangerous than in humans. Anesthesia is a benefit in that it is easier to adjust the joints for a good reading with a dog that is knocked out. My impression is that it takes some skill and experience to get good at OFA filming of dogs without anesthesia--definately one case where I would ask your vet how experienced they are and go elsewhere if you don't like the answer.

Official OFA results are not posted for dogs less than 2 years of age, whereas PennHip can go much younger. Some say PennHip is more prone to falsely predicting displasia in younger dogs though--again, they predict the possibility of it through joint laxity more than OFA which looks more at actual current hip/joint problems. Some dogs who don't do that well in Pennhip--particularly very young dogs--may get a poor Pennhip reading but never develop CHD.

Pennhip does appear to be a better measure of potential problems to me, but I would not do it early due to what appears to be a greater chance of a poor test in a dog that never does have problems later in life.

My belief is that Pennhip's advantages fall away when you are working with a dog whose close ancestors all have good or better OFA ratings and no evidence of hip problems later in life.

I also think it's a rare stud that should be bred before two years of age, same for bitches. Taking a chance on that now as I just bred my bitch to a nice stud a few weeks shy of his 2nd birthday--but his prelim OFA was OK and hips were all OK going back in his parents and further--some pretty well known trial dogs. Should have the official OFA reading soon, before pups are sold.

Last thing I'd say is I've occasionally seen some folks say that success in demanding field events--e.g. all-age field trials--ought to be proof enough of lack of CHD. Some folks who claim that don't run their dogs through OFA or Pennhip. I don't like that and wouldn't buy a pup from them no matter how nice it looked.

That's my 2 cents. Hope it doesn't muddy the waters too much.

Posted: Tue Mar 13, 2007 9:59 am
by TNovoa
Here's, what I found to be, an interesting view on OFA and PennHip:

http://www.showdogsupersite.com/ofa.html

If you go back to the main site, I also found the article on unilateral HD a good read too. There's actually a lot of good articles but I thought I'd stick with hips here. :wink:

OFA hip readings of good and excellent are what most people prefer to have in their breeding programs. A fair rating is not borderline dysplastic. I have a fair bitch who's sockets are shallow and do not encase the ball of the hip joint like a good or excellent would. She is not dysplastic though. In her case, I would choose a stud with a good foundation of hip structure to improve upon hers.

A friend of mine has a bitch who OFA'd fair and PennHip'd with a DI of .71 ("more than likely to develop DJD"). This dog is nowhere near being impaired by CHD or DJD in her hips, at now, 12 years of age.

Hip clearances, among others, are very important and either test will give you an idea of whether or not to use this dog in a breeding program.

OFA vs. PennHIP

Posted: Wed Mar 21, 2007 12:40 pm
by Wildflugel
I had posted the following information regarding PennHIP on a different discussion forum. I am happy to share this information to help you decide if PennHIP is right for you and your dog. I apologize in advance for the length of this post.

I routinely have two hip evaluations performed on my dogs. One set of x-rays is submitted to Germany and the other to PennHIP. I am all for any procedure that takes the subjectivity out of evaluating x-rays (OFA) and replaces it with objective evaluations (PennHIP). I did some research before deciding on whether to use the PennHIP method my vet suggested and found the following.

The University of Pennsylvania Hip Improvement Program (PennHIP) was based on the work done by Drs. Gail K. Smith, Darryl Biery, and Thomas Gregor. Dr. Smith is a Veterinary Orthopedic Surgeon at the University of Pennsylvania, holds a PhD in Engineering, and was the lead in the development of this technique. I was not able to find much information regarding the background of the other two doctors.

The development of PennHIP involved several disciplines including biomechanics, clinical medicine, radiology, population genetics, and associated statistical analysis. The principle behind PennHIP, as a diagnostic tool, is that hip laxity is a measurable component that can be used to predict a dog's susceptibility to develop canine hip dysplasia (CHD) and degenerative joint disease (DJD) later in life. By applying the physical principles and biomechanical testing of the hip, PennHIP stress-radiographic methods can accurately measure hip joint laxity in dogs as young as 16 weeks. PennHIP requires that x-rays be submitted for evaluation regardless of whether the owner wants to or not. This differs from OFA in that the owner can decide whether to submit the x-rays for evaluation.

The primary difference in the PennHIP radiographic and diagnostic method and OFA is in the positioning of the dog during the x-ray procedure. Dr. Smith believes that a measurable amount of hip laxity is inherent in all dogs. The PennHIP method was developed to quantify the relative degree of femoral head displacement from the hip joint visible in a compression distraction view. This view requires the dog to be under deep sedation or general anesthesia and incorporates two views of the dog in the supine position and one view of the hips at a neutral position. Dr. Smith also believes the compression/distraction stress radiographic technique is 2.5 times more sensitive in quantifying hip joint laxity than the standard hip-extended method (OFA).

PennHIP's range of laxity is quantified on a Distraction Index (DI) scale from zero to 1. Hips approaching zero are extremely tight and hips approaching 1 are extremely lax and 100 percent out of the joint. The PennHIP method provides a "distraction index (DI)" score for each animal that is evaluated. Hips that show very low laxity (low DI score) are considered tight hips that are highly unlikely to have evidence of DJD.

As stated by PennHIP, their primary objective is to provide reliable, quantitative information to dog breeders that will allow them to make breeding decisions that can reduce the incidence of DJD and CHD in their lines. It is important to understand that PennHIP is not evaluating the animal in the familiar “pass/fail” manner. A given DI score does not exclude that animal from breeding consideration. What the DI offers the breeder is an understanding of where their individual animal ranks relative to other members of its breed (or the overall dog population if fewer than 20 bred members have been evaluated) with respect to hip joint laxity.

The guiding principle evolving from the PennHIP research suggests
“tighter hips are better hips and breeding tight hips to tight hips is the best approach rather than trying to breed looser hips to tight hips.” Is PennHIP 100% accurate, absolutely not. However, I personally believe it is the best method available today simply because none of the other evaluation methods has undergone testing through controlled scientific testing.

In my opinion there are a couple of reasons that prevent PennHIP from being utilized by breeders and owners more than it is right now. The first is the cost. The cost for PennHIP is significantly higher than OFA. The cost differential is because OFA requires a single x-ray of one position while PennHIP that requires three x-rays of the dog’s hips. I have found that the vet community has not established a standard fee when performing PennHIP x-rays.

I live in central Nebraska used to drive to Iowa State University to get my dogs PennHIP. Even though there are vets certified for PennHIP in both Lincoln and Omaha, I found it is cheaper to drive to Ames, IA than use the vets in Nebraska. There is now a vet in north-central Nebraska that is certified to perform PennHIP and the last time I was charged $200 for the exam, sedation, x-rays, and evaluation fee, this is extremely reasonable. The PennHIP web site can help you locate certified vets. The best thing to do is once you get some names is to contact them individually to see what they charge.

I also believe that people have more of a comfort level with OFA than PennHIP. Several years ago, I contacted both PennHip and OFA regarding the number of dogs in their databases. PennHIP responded and told me that as of September 2000 there were 29,479 dogs in their database. OFA sent me an E-mail stating there was 825,000 dogs their database. Please note that I did not inquiry as to the number of breed categories and/or the total number of dogs within any given breed category. I am sure this information is available and PennHIP would be more than willing to share this data if asked.

I think that PennHIP is still being viewed as the “new kid on the block” by some people. These same individuals want to look at more information to see if the PennHIP predictions regarding laxity and CHD are in true. There is a web site for PennHIP that has some very good information along with some frequently asked Q&A. The site address is: http://www.vet.upenn.edu/ResearchCenters/pennhip I have a list of references regarding PennHIP if you are interested. It is too long to post here, but if you send me a PM, I will send you the list.

When I was doing research on PennHIP, I came across the following interview with Dr. Gail Smith, University of Pennsylvania. The interview occurred in June 1995. I am posting a few of the questions and Dr. Smith's responses. You can see the entire interview at http://bullmastiffinfo.tripod.com/pennhip1.html I hope the following information helps answer some of your questions.

Question: Did that paper (referring to a 1989 research paper on examination of human infant hips where Dr. Corley with OFA raises the question that the examination procedure in the infant may actually cause a stable hip to become unstable) present any actual data documenting real harm done by the technique?

Dr. Smith: For the PennHIP procedure, the hips are placed in a neutral (stance-phase) position and a small harmless distractive force is applied to displace the femoral heads laterally from the acetabula. I am not aware of any such reports (studies that document harmful effects) and I am confident that if such documentation existed, it would have already been brought to the attention of the breeding public by the OFA. One should not lose sight of the fact that the OFA position is itself a stress-radiographic method that to my knowledge has not undergone safety testing. Also, it must be recognized that the PennHIP procedure specifies that an OFA radiograph be made for each compression and distraction view made (for a total of three views). After many studies and much close scrutiny of our data, we have no evidence to suggest that the procedure is any more harmful than the OFA stress-radiographic procedure.

Question: Do you think that the PennHIP procedure might cause an otherwise healthy adult dog, without CHD (canine hip dysplasia), to go on to develop joint disease? What about 4-6 month old puppies whose skeletal systems are not yet matured?

Dr. Smith: No. Not a single tight-hipped dog, irrespective of breed and age of first evaluation, has yet developed signs of DJD (degenerative joint disease) regardless of number of distraction procedures done throughout its lifetime. Longest follow-up is 9 years.

Question: What about a dog that has CHD, could it be worsened by the PennHIP exam?

Dr. Smith: Dogs with extant, clinically apparent disease can suffer transient discomfort stemming from any manipulation of the hip even routine orthopedic examinations.

Question: To the best of your knowledge, has anyone ever reported to you or to ICG (International Canine Genetics) that their dog developed hip problems as a result of the PennHIP procedure? If yes, how many such reports in how many years?

Dr. Smith: Of the more than 6,000 dogs evaluated thus far using the PennHIP procedure (3 radiographic views including the OFA view), fewer than 6 owners have reported that they thought the process may have cause temporary discomfort. No long-term complications have been reported. Could a dog that has no clinical symptoms of CHD, but has loose hips be at risk for harm from the exam? Dogs presenting without clinical signs are not made clinically painful in the short term by the evaluation procedure. In the long term, loose-hipped dogs having multiple PennHIP evaluations over their life appear to be no more at risk for developing osteoarthritis than those evaluated for the first time as an adult.

Question: In your opinion, is the PennHIP method any more or less risky to the dog than the positioning done for an OFA x-ray?

Dr. Smith: In my opinion, the distraction procedure is less painful than the OFA procedure. I feel neither procedure has measurable risk for ill effects to the dog.

Wildflugel

Posted: Wed Mar 21, 2007 1:35 pm
by TNovoa
The most common reason most people lean toward OFA is their relationship with AKC. PennHIP results do not show up on AKC pedigrees nor does PennHIP have an easily accessible research database set up like OFA does. That is sad. They need to get with the program and on the front lines!

Posted: Wed Mar 21, 2007 2:13 pm
by Wildflugel
In reading the various discussions on other retriever and hunting forums that I visit the primary two primary reasons cited for not going with PennHIP are cost and the fact that the dog must be sedated to take the films.

I was looking at PennHIP's web site and found the following regarding AKC's recognition of PennHIP results: In 1996, the AKC board of directors announced plans to remove all health and genetic information from the official AKC registration and to include it along with PennHIP information in the newly conceived "Information and Health Database". We have recently learned (July 1998) that the AKC plans to re-energize this initiative. We anxiously await progress from the AKC on this very important issue.

Hopefully in the near future AKC will get the database up and running.

Wildflugel

Posted: Wed Mar 21, 2007 7:33 pm
by Windyhills
Wildflugel wrote:....the primary two primary reasons cited for not going with PennHIP are cost and the fact that the dog must be sedated to take the films.
Sedation is not as trouble-free in animals as it is in people--so I can't blame people for being a little concerned there. Another factor I would point out is that chances that your normal vet will conduct a Pennhip evaluation is much less than their handling OFA for you.

Just as you can find Pennhip proponents taking OFA to task, one can easily find OFA information questioning the use of Pennhip out there as well--supported by scientific references.

Namely that it's use as a predictor (remember it does not measure actual disease but uses joint laxity as a predictor of future problems) is still premature, and there aren't enough dogs that have been through Pennhipp and then followed up in life to suggest it's superiority yet.

That info is a bit dated and it does seem to me that PennHip has earned it's stripes, but it is still not without it's own issues. My vet for example had some concerns about the process used in PennHip. OFA is not as hard on a dog but then it's easier to get a poor reading from it than Pennhip if the vets doing it don't know their stuff.

For someone really serious about checking a line of their own dogs, I might run both--Pennhip early, OFA later on in life, then not breed any dogs with problems at either step.

Posted: Sat Mar 24, 2007 10:29 am
by Ruffshooter
Personally I like Penn HIP simply because there is no judgement. It is a physical measurement that I can see and understand and it is documented. Ten different OFA evaluators can get every rating there is on the same dog. They are just looking at the xrays based on the whole dog race and comparing it to everything large and small. (People see things differently and have there own ideas of what could be a problem. I know of a dog in Canada that I was told about prior to complete computer refinements that got every rating there is on this one dog. (some shicanary with numbers).

I have done on of my French Britts at I think 9 months old. He came in with .33 in each hip. For chuckles I did it again at 4 years old. He had one hip come in at .33 and the other at .35. I don't know if the .35 hip was due to an injury he got to the hind end hunting or not. But I would say that is pretty consistent. .54 is the Brittany average. The closer to .30 the better. Supposedly less anomolies that could result in hip problems down the road. I do all my dogs Penn HIP.

Each BREED is tested and put into a data base specifically for that breed. The information on the breeor your own breeding can be tracked. You can use that information to help make decisions for dogs to be bred along with other pertinent info.

I never much thought a Fair rating was something that one should consider as good enough to breed.
OFA?
If it is fair, then it is not good, then there is something wrong. IMO