The PennHIP Radiograph, page 2
Rationale, Technique, Differences, and Value
by Fred Lanting

[This paper is � copyrighted and may only be used for information
purposes. It is the sole property of the author and any commercial
use or reproduction without written permission is prohibited.]

Advantages
The great value of PennHIP is the higher accuracy and reliability of evaluations done at an early age, so owners don't spend more money than necessary in training for more demanding work, or even breed a dog that has a relatively high risk of later transmitting many bad genes to progeny, or itself developing DJD. The accuracy and repeatability of DI is just about as valid at six months age as throughout life; in fact about 95% reliability is seen in pups even as young as four months. The report by OFA that they too, now have equal predictive value (JAVMA, 1997) was refuted by a University of Wisconsin study published later and has not been confirmed by other independent research. Similarly, the OFA claim of progress in the past quarter-century has not been supported by data or experience elsewhere. The claims in their news release were reduced to just a 2.83% increase by the time the article was reviewed and then published in JAVMA in 1997; that would indicate that the inflated numbers in the OFA mailings to clubs might not be all that impressive. All that our reliance on OFA numbers has done is to allow very slow, perhaps almost imperceptible, progress in some lines of some breeds and, in a statistically insignificant amount, the "excellent" ratings in a few breeds. In almost all others, more than thirty-five years of partial use of OFA for breeding decisions has resulted in no progress, and in a few breeds the situation may actually have worsened. Breeders complain of a plateau reached in rates of progress when relying solely on OFA certification.

During the seminar on HD and other orthopedic disorders that I have presented in many countries, I recommend a few points to keep in mind when comparing the methods:

1. PennHIP is the hip-extended view plus two more radiographs that show different things,

2. PennHIP has performed biomechanical studies on its radiographic positioning while others have not,

3. PennHIP has performed much research in general and these have been published in refereed journals to prove the science is valid. Those who quote old information and say that "School is still out on the PennHIP method" simply have been skipping classes in the past several years.

To replace the old combined-approach program of Bardens palpation, wedge X-ray, and OFA-Good or Excellent, today I recommend PennHIP's improved technology at 4-6 months (or any time before breeding) as a viable and more accurate evaluation than all three of those. For breeding, I advise my audiences to breed only to a partner with higher than 50th percentile and lower DI than the mean, or a lower DI than their own dog has; if they really want to accelerate progress, to breed dogs with 0.3 or better. At least, get as close to that threshold as possible, consistent with preservation of breed type and character.

What Does This Mean? The Situation Today: Slow Progress and Why
Why, after nearly some four decades of awareness, breeding changes, and study, do we continue to hear from disgruntled or dissatisfied dog buyers and breeders? Knowing that orthopedic disorders are almost all genetic, one might think that it would be a simple answer to just breed non-carriers of HD or ED (elbow disorders), or those with the best genetic bank for good joints, but it is discovering these dogs that is the challenge. Now that we have good diagnostic tools and effective hip registries, the next step toward progress is for each breeder to develop a breeding program. Fortunately, some breed clubs and other organizations have already done the greater part of laying a foundation. We have already potentially removed one of the two major obstacles to progress, lack of understanding - or in other words, a lack of good diagnostic guidance. After decades of using the hip-extended method, most or all of those agencies have not generated a reliable heritability figure for hip phenotype, nor has the method used in North America reduced the incidence of HD as an average, across the breed populations. Even when we look at subsets of canine populations in the serious hobbyist world, whether we speak of individual or group (club) efforts, we find that discontinued progress. One reason is the failure to adopt the better diagnostic techniques.

The other reason for insufficient progress in reducing and ultimately eliminating canine HD is non-compliance: the failure of most breeders to stick with a really vigorous program of control and reduction. As you might think, some breeders do their best to provide an environment that causes the least dysplasia. However, genes that induce HD will thus be masked and therefore retained in the stock. Few breeders are likely to provide knowingly the adverse eugenics environment that would reveal such genes. Part of that second reason (breeding practices) for slow progress is the win-at-all-costs attitude maintained by many of the more prolific breeders and leaders of breed clubs. In 1986 John Bardens, a friend and a widely respected veterinary researcher, wrote to me, "Many of the breeding [genetic] defects do not hit the breeder in the pocketbook, and winning in the show ring is all that's important."

In some parts of the world, organizations and individuals have made greater strides than those in North America have, but there is still a way to go. The requirement in Germany for all radiographs to be recorded and dogs' results made known, is admirable. The "sometime-pressure" in the UK for vets to cooperate by sending in all films and getting the results posted in the GSD database founded by Dr. Malcolm Willis has helped a little. "Kiwis and Aussies" down-under use the UK system, but also have room for improvement, as the following example would indicate: I received a request for advice and counsel from a breeder in Australasia who sold a pet-price bitch (no guarantees), paid for the 12-month radiograph, and got a BVA-type score of 11 in the Australian hip scheme. When the bitch was approximately 3 years old, the buyers decided they wanted to breed her, had her re-radiographed, and the score was 81. Now, 11 is pretty good but 81 certainly is not. There are two likely reasons for the two different readings, and I suspect both are involved, even though the bitch had no clinical signs. One is the inaccuracy of the supine, legs-extended procedure used in diagnosis in the bulk of the world. The other is the rule rather than the exception that loose hips at a young age (even if undetected) can be even looser at an older age, when examined by the old method, and that DJD (degenerative joint disease, arthritis, remodeling) is more likely then. On the other hand, the experience with the great majority of cases evaluated with the PennHIP method tells us that true laxity does not change significantly after 4 months of age. At least, it is a rare occurrence. If the prevailing culture and conventional wisdom amongst breeders and vets in New Zealand and Australia ignores the newer, improved, more accurate techniques, can they rightly blame the average breeder? However, using a method shown to be not the best available opens the door to litigation if defects should appear.

Progress in the United Kingdom
England, Scotland, Wales, and to a lesser extent countries with historical ties to England, such as Ireland, Singapore, "OZ and NZ", South Africa, and a few others have the potential for making great strides in reducing HD. Part of the mechanism is in place; what breeders need to do is use it. However, it may be difficult to accomplish without government legislation or regulation by breed clubs and The Kennel Club. They certify hips at one year of age; whether by government force or voluntary peer pressure, I would like to see a reconfirmation of phenotype normalcy after 2 years of age. Where the UK scheme continues to fall short of being ideal, besides certifying at an early age, is in not requiring all films to be submitted for the statistical study.

The BVA system concerns nine features; values of zero (no irregularities) to 6 (horrible) are given to both left and right hips joints, and the columns added. Most good breeders refuse to use any dog with a grand total of anything more than 10. Dr. Malcolm Willis, for many breeds, reports results with dogs' identities, in a form useful to breeders. The British Veterinary Association's scheme was adopted or copied in several countries historically connected to the old Empire. Besides giving a quantitative score, the BVA/GSDL/KC scheme also has another important advantage for breeders over the American OFA and some other systems: it does produce information on progeny for several breeds. Computer-retrievable data by kennel name, sex, birthdate, age at time of radiography, and numerical value for each hip are used for genetic analyses and for your own conclusions on with whom to breed Schatzie, or whether to breed at all in deference to waiting to buy a better dog. Say you like the looks of that dog that placed in the Top Ten at his breed's national specialty show the past two or three years. You look up his published hip scores, the mean score of his offspring who are old enough to be assessed, and scan the column that tells you whether and by how much he improved on the hip scores of bitches he previously bred. If your breed club doesn't have that information, and it's likely it doesn't, then it isn't doing all it can to serve you and your breed. That's where "politics" can have a rare, beneficial effect on purebred dogs and the sport. Get into or start a movement to require your national club to hire a geneticist and give instructions to set up a scheme similar to that now employed by BVA/KC. Yes, you can go it alone, but your choices of breeding animals will be more limited than if you were backed with the power of a club like the U.K.'s GSD League or BAGS, or the GSD Council of Australia.

However, despite one of the most advanced information and control schemes in the world, the mean scores for GSD males and females born in the UK since 1959 have not changed a whit. About 45% of the UK's GSDs have scores of 10 or below, with most considering the really "normal" ones as being in the 0-5 range and the 6-10s being equivalent to what we might call "near-normal". BVA scores as high as 20 could encompass the level of quality in dogs given the 'A' stamp in Australia (not the same meaning as the FCI's "A" designation for normal hips), but allowing that many dogs to breed will slow the progress, regardless of breed or country. Much better to make the requirements more strict each year until something approaching the Swedish model can be had. Progeny data are often seen in tables published in breed magazines. Obviously, those sires that produce higher percentages in the 0-5 score category and (of slightly lesser importance) a close second-high percentage in the 6-10 column, are the most desirable for improvement in hips and should be preferentially bred to, as long as they also produce other important good features.

Progress in Australia
I was an honored guest and minor judging participant at Australia's 1991version of a "Sieger Show", the only foreigner to have been so honored up to that date. It is called the "Main Breed Assessment" rather than a "show", to avoid problems with the quasi-governmental Australian National Kennel Council over practices allowed at regular shows, such as pedigrees and catalogs in the judges' hands, gun sureness testing, and especially information on what problems and good features the dog being examined has passed on to its pups. I was very impressed that, in coming to the placement decisions, the judges of the adult classes took into account such things as the Australian 'A' stamp hip status (they capitalize the letter there) of the individual as well as of siblings and offspring, and other genetic factors as well as a full and expert evaluation of the dog in question. The GSD people in Australia modified the BVA scheme in conjunction with their own system. But I think they give the 'A' stamp to too many animals for fast enough progress. The 6 grades are: N, NN, A, BL, III, and IV. Dogs are considered eligible for the 'A' stamp if they have one of the four top grades of the six, and this includes A (acceptable) and Borderline (many of which have what OFA would call mild to moderate HD). As in Germany, this allows too many to breed, and tends to act as a brake on progress. However, they have what we in North America don't have, to any appreciable amount: progeny data. This tends to offset part of the failings of less-strict radiograph requirements, at least when comparing those schemes to OFA's. According to an issue of the Australian GSD club's newsletter, almost all of the Normals and 61.4% of the Near-Normals score 0-5. While GSD hip quality has not increased as dramatically as quality of breed type, there are hip requirements for breeding and, in time, increased strictures will produce faster improvement. By limiting breedings to animals with the 'A' stamp, the Aussies and New Zealanders would exclude about a third of the breed, better than what was done in England, but far inferior to Sweden and what had been required in East Germany. Since 1981, the percentage of Australian GSDs receiving the 'A' stamp has risen from 60% to 80%, while grades III and IV (roughly equivalent to moderate and severe HD in the United States or the BVA scores of 0-10) have declined by half.

Japan and Pacific Rim
In the modern, dog-loving portion of Japan's society, progress in control of hip dysplasia is just around the corner. I have judged and lectured there, and long ago found great interest in improving many areas. The Japan Kennel Club adopted PennHIP as the official and preferred HD diagnostic procedure in the late 1990s. In Taiwan, dog shows and interest in improved breeding, including for better hips, are on the increase. When I lectured in Malaysia and the Philippines, I found the progress and awareness at a lower level, but at least they know enough to ask about hip status when they import dogs for their breeding programs.

Comparing America to the World
In the Americas, the oldest hip registry is the OFA, but there are two better ones in many respects: GDC (Institute for Genetic Disease Control) and PennHIP. It's a good thing that OFA requires a minimum age of 24 months for certification of "normalcy"; otherwise the situation in most breeds in the USA would be dismally poorer. In most breeds it is not that great, anyway, if you look at over-all breed statistics instead of individual breeders' accomplishments. Paradoxically, the greatest rates of progress are in some of those countries where dogs are radiographed and certified for breeding as soon as they pass their first year's birthdate, although they would be even better if approval were to be delayed at least 6 more months. The reason, though, is that many breed clubs outside America control authorization for breeding and registering. In America, the AKC gleefully registers anything that comes with money and the specified paperwork.

Compare progress in the U.S. with that in Germany, for example, and specifically the most popular breed there and in the world, the German Shepherd Dog. There has been a shift toward normalcy that came about in spite of the practice of forbidding breeding rights only to those with severe HD. As time went on, requirements for the VA (excellent-select) class at the world Sieger Show in Germany were tightened more and more. Not only must current highly placing show dogs have advanced training degrees, they must also have the better hips and produce a good number of normal hips as well as structurally desirable progeny. Today a dog with a Noch Zugelassen (still permissible) rating might make it into the VA class of some eight or ten dogs out of hundreds of competitors, but he or she will not win the top title of Sieger or Siegerin, and there is now pressure to keep the bad producers (with high ZW numbers) from being honored with the Sieger title. There is annually increasing emphasis that the very top be Normal, not just Fast (nearly) Normal. So the dogs that get the most breedings in most of Europe will generally have the best hips. There is no similar restriction in the sizeable Select class for GSDs, neither at American (U.S.) national specialty shows, nor at the smaller but similar Canadian Nationals. Nor is there anything similar in the other AKC- or CKC-affiliated breed clubs. In America we have neither the strict rules nor the peer pressure nor strong suggestions to judges. We certainly aren't allowed to officially "know" the hip status or other information important to the breed when we judge.

Even faster progress could have been made by the SV if they would award the "a" stamp only to dogs radiographed after 18 or 24 months of age. And in other countries we could see an increase in the progress rates if all dogs were to be radiographed and evaluated, even if they had poor hips and would never be bred. It would give valuable data for progeny testing.

Improve Your Breed by Improved Breeding
I recommend that breeders use this triad: evaluating mature dogs for DJD, using PennHIP for early risk detection, and following a Breed Value/Zuchtwert program. If, as is certainly indicated, the DI gives a better picture of future hip quality in your dog, then deductive reasoning would lead you to think of it as a reasonably accurate indicator of the genotype of your dog. That means a better idea of the proportion of bad hip genes to good hip genes, which in turn means relatively how many bad genes are likely to be transmitted to the next generation Now that, dear friends, is really revolutionary. The lack of further progress we have seen in modern times, with ratings by BVA, OFA, SV, ADRK, OVC, and other breed and veterinary organizations is a direct result of their inability to indicate those hidden genes. A dog that has a good picture in the extended-leg view yet still produces an unacceptably high number of dysplastic offspring has too many of those hidden genes. Since OFA would be the first to tell you of the link between laxity and HD (remember, they actually use that as a definition), the only reason for the poor progress is the covert laxity I mentioned earlier. Therefore, using a logical process of thought, if PennHIP shows more of this laxity than shows up in the AVMA-type view, it better shows us the effects of more "hip genes". Since mapping the dog's genome (at least finding markers for enough of the polygenic perpetrators) is decades away, the DI evaluation as promoted by PennHIP is by far the best tool in our tool chest.

Editor's note: Fred Lanting, [email protected], offers seminars on a variety of topics, such as orthopedic disorders, gait-&-structure, basic genetics, the evolution of the German Shepherd Dog, and other subjects. He consults on these and behavioral problems and can be reached at home in Union Grove, Alabama when he isn't on the road judging. He has many years experience as an AKC judge, and is an all-breed judge for UKC and several other registries. Additional articles may be found on his co-owner's website www.vonsalix.faithweb.com, or on www.realgsd.net and others.

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This Oct. 2001 revision may be reproduced in newsletters and websites. Please confirm or notify by e-mail.

This paper is � copyrighted and may only be used for information
purposes. It is the sole property of the author and any commercial use or reproduction without permission is prohibited.

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Thank you Mr. Lanting for giving me permission to reprint your article. Dog owners as myself appreciate the time and energy you put into gathering and articulating this information into easily understood format. Keep up the good work!

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If you know of any well written articles or know about Holistic/Alternative/Complimentary method of treatment pertaining to pet health I would like to know! I am always looking for more educational material to add to this new section of Bodhi's Site. Please contact, Desiree Thank you!

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