Why OFA and the "A" Stamp Aren't Good Enough - Page 1

When I had Star's hips evaluated last month, the right hip turned out to be mildly dysplastic (subluxation, meaning it was partly out of the socket.)

This came as a surprise, as her pedigree shows her ancestors had good hips. The only 'bad' hips are three generations back, and those were two dogs that rated 'fast normal' under the German rating system, which is equivalent to the OFA rating of 'borderline'.

Wondering how common it was for this to happen, I decided to e-mail Fred Lanting, who has written a book on canine hip dysplasia.

Here is his response:

Jane, I hope you will go to my articles on the siriusdog.com website and study those re PennHIP. You have fallen for a couple of errors that are commonly obstacles to progress in breeding programs. Better yet, order the orthopedics book.

First, to rely on the highly unreliable OFA readings and SV "a"-stamps, is a bad idea. There are many, many dogs with unacceptable-for-breeding laxity in the hips, who (because of the positioning used by OFA, SV, etc.) LOOK normal, but are not... the only way you can see the incipient, hidden laxity is with the distraction view, such as PennHIP has perfected.

When you say her ancestors all had "good" hips, I'd bet that they were not all really that good, but that several of them sneaked by, in this v-d position which artificially tightens up the ligaments around the hip socket and femoral head. The old systems were so inadequate that the PennHIP system was developed to correct their failings. All you know about the ancestors is that at the age they were X-rayed (12 mo. for the German, 24 mo.+ for the others) is that they weren't absolutely horrible. But you DON'T know HOW good (or that they were not so good). I hope you have the book (see attached). Or will order copies right away.

So, you see, it wasn't a bolt out of the blue. It was just something that was there all along (probably for generations in depth) and you had your dark glasses on, in the dark. Fred

Feel free to fwd those comments.


I knew that Fred had recommended Penn Hip rather than OFA, but due to certain flaws in Star's structure, I was already starting to doubt whether I should breed her, so I decided to go for the less expensive OFA evaluation. Also, living where I do, the nearest vet qualified to do OFA x-rays was over an hour away!

Anyway, with her hips being bad under the OFA system, no doubt the Penn hip evaluation would have said the same thing. The only way to avoid having this happen is to get more breeders to Penn-hip their dogs, then NOT breed the ones that don't pass!

Fast Normal does NOT EQUAL BORDERLINE DYSPLASTIC

When you look at stats in Germany or here - 20% +/- are Dysplastic

the rest are spread through a1, a2, a3  or Excellent (3% +/-) Good & Fair  -   a1 DOES NOT = Excellent either!  Those 3% Ex will fall into the a1s -   a3/C FCI hips can and have gone OFA Good, a2/B FCIs have gone OFA Good and even Excellent

The best thing is not just to rely on the ratings but to see the x-rays of the hips of both parents if possible to look at the sockets and balls yourself

I PennHIP my dogs as I like how it is not subjective, but there really isn't a clear pass/fail with this system.  PennHIP states that a GSD with a DI (Distraction Index) of under .30 is highly unlikely to ever have DJD (Degenerative Joint Disease).  A GSD with a .7 is highly likely to have or later develope DJD.  They recommend only breeding the better half of the dogs they have rated, which would be approximately .45 and lower.  These numbers will continue to change as the dogs in their database change.    Statistically the GSD is more susceptible to DJD with a lower DI (.7), while most breeds the DJD line is around .9, and the better half is approximately .55 and lower.  I can't help but wonder if most of the x-rays from GSDs are from American lines, which generally are more angulated, and therefore I would expect need tigher hips to not develope DJD.  With PennHIPs, it allows the breeder to draw their own line, as again, there is no clear pass/fail, only suggestions and statistics.

Thanks for posting that Sunsilver

I think without the test of time and the evaluation of the dogs actual functioning and abilities on the ground the Stamps and Penn-hip and OFA are only guide lines.  And five generations back in time you really have to wonder what the dogs were really like.
I always want to know how long the dog lived and how well did the dog function over its lifetime.

How does OFA compare to Penn Hip?  Penn hip recommends that dogs chosen for breeding have a DI equal to or less than 0.3. This means that at least 70% of the femoral head is covered by the hip socket.

Fred cites the following statistics in his book:

53% of OFA Excellents were looser than 0.3 DI
64% of OFA Goods were looser  (the loosest had a 0.77 DI)  !!!
93% of OFA Fairs were looser than 0.3 DI
77% of all OFA "Normals" combined had DI of greater than 0.3 (were looser)

He also reports that many of the registries' data and statistics are skewed because not all films are sent in. This means that if the x-ray shows hips that are obviously horrible, the owner has the option to tell the vet NOT TO SEND THE X-RAY in!

The SV and Penn Hip are two of the registries that do require the films to be sent. The OFA and BVA registries do not, although the BVA 'strongly recommends it'.

Thanks for bringing Pennhipp to light here. It is a fantastic and very accurate tool that not enough people know about. I look forward to the day when we can lose the old way of OFA and be more informed about Pennhipp. The test is much better way to compare your dog to it's own breed and measures actual laxity of the socket. I personally have only used the Pennhip with my dogs and am proud to say they fall in the high 80th percentile and at .30.
I too am puzzled that with all the progress and knowledge on breeders part to be informed about hips and the ratings that our dogs are not improving as fast as would be thought?
What more can we do to remove this problem from our breed?
Shelby

sunsilver , I had multiple dogs xrayed and send the pictures for evaluation to both FCI  (netherlands) and OFA  ,and some to holland and germany to compare
 to get a good picture from one versus the other , and I havent found one chart on the internet that even comes close to my findings

maybe if I do some digging I can find the original records

whith great respect for fred ( whom I personally now a bit) I have to disagree with him

getting bad hips out of good parents has nothing to do with bad pictures or bad evaluations(however this can occur ocasionally)
It has everything to do with genetics , envirement and cheating

if people wont recognize this , and  tackle this , you wont make progression at this

no pills or different way of xray will cure this

A good friend has a female Am. SL that is from 6 generations of OFA certified breeding. 8 of 9 siblings in her litter are OFA certified. From this litter I could make the statement that 88% of dogs from 6 gens. of OFA  (that I have studied) will have good hips.  Not very scientific, but certainly a true statement.

I think that "a" stamp or ofa certification should be at least the minimum standard for breeding.
 
While I understand that there is a certain amount of subjectivity in the reading of X-rays, there are also varying opinions from very experienced dog people on which evaluation is better.

If Penn Hip stamps out HD in a few generations, then there will be no more need for debate.

Also keep in mind that in the U.S. it is very easy for an unethical person use a substitute dog for x-rays if one has a top dog with known bad hips.

Rik