Why Small-dog Breeders Might Look into PennHIP
Is It Useful for the Smaller Breeds?
People take actions based not so much on logic and reasoning as on emotional bases. This is something I learned in some 33 years in the business of chemicals marketing. I saw the same thing in my experience as a breeder since the '40s, a handler since the '60s, and a judge since the '70s. And it's been a hard lesson for me to assimilate, because I am the penultimate logic-based person. So much so that I've been accused by some as not only being from Mars (women are from Venus) but from the dark side of a moon of Mars! Trained in the scientific method, which is based on careful observation and collection of facts, cause-and-effect, testing and proving all things (including following the Scriptural admonition in I Thessalonians 5:21 to do that very thing), I never quite learned complete patience with those who would not use analytical processing of data to come up with a sensible conclusion and subsequent actions.
That said, I must acknowledge that even among those who attempt to use and follow precepts of science and logic, there will be emotion-mediated decisions and courses of action. Take for example the decisions relating to canine hip joint integrity. I think we can all agree that HD (hip dysplasia) is a serious problem, and that only a few ostrich-brained relics are still sticking their heads in the sands of ignorance and avoidance, claiming HD to be simply or mostly an environmental problem. Even among the ranks of the cognoscenti, however, there are those who hang onto the hope of a “magic pill” approach, like Linus clutching his security blanket, or a religious person holding by his fingernails the notion that his good aspects should outweigh his bad ones at the final judgement. Vitamin C or seaweed or chicken joints or anything else that comes along with the false promise of an easy, mystical or non-understandable (or rationalized) way out of the suffering that severe HD can bring—any of these approaches are emotional roads to the goal of better dogs. Only their proponents have unintentionally or ignorantly twisted the road signs to make you think they are accurately pointing to the same destination. Only the hardcore of those who want the easy ways out are today avoiding the logical, science-supported fact that HD is essentially a genetic disorder and can only be finally dealt with by selecting breeding partners. You can sometimes ease the life of one afflicted by modifying the environment through nutrition, bedding, temperature, etc., but you cannot change the genes.
As my nephews and grandchildren used to call the dinosaur days when this Grandpa was a kid “the olden times,” people who wanted to avoid the health problems looked to the proven working dog breeder for their stock. My principal breeds in recent years have been the German Shepherd Dog and the Shiba. When von Stephanitz and colleagues were establishing the GSD breed a hundred years ago and more, they looked down their noses at “the city dog” because they saw many health deficiencies among those communities; the working farm and sheep dogs, the “country dogs,” were sturdier, longer-lived, and more resistant to almost everything. Von Stephanitz liked to tell of the sheepherder who, after a full day's work with the flock (dog running a good 10 hours) bicycled many miles to a trial with his dog trotting beside him, competed in it, and made the long trek home again. Sled dog racers before the snowmobile era used to mush across great expanses of wilderness; this is duplicated today on a smaller scale, in order to race from Juneau to Nome or similar competitions. This type of demanding work eliminated the dogs with bad hips from most of the breeding opportunities.
Less strenuous but similar work did not have the same effect, as discovered by Australian Shepherd breeder and vet John Pharr who with Dr. Joe Morgan studied HD in the working stock dogs of his breed and found more than half of them to be dysplastic. Apparently modern dogs, in this hemisphere at least, are not pressed to the same limits that uncovered weaknesses and eliminated HD in bygone gene pools. We just don't work our dogs today in any way that comes close to natural selection. The Shiba in its early years of discovery and re-establishment was very close in many ways to its primary progenitor, the Dingo (or its near ancestors). Wild canids have very low incidences of HD partly because of the laws of Survival of the Fittest and Natural Selection. As the Shiba, like the GSD, became a “city dog” and identified more with Tokyo apartments and tiny roof gardens than with the demands of hunting, weaker individuals were allowed to breed as often as those that had proven themselves in endurance, fighting game, and jumping high to catch flushed birds. Even its mixed descendant, the Akita, bred by war lords for prestige through dog fighting, did not have to work every day. Both breeds developed “HD by neglect,” which is the mode still in effect. Survival of the fittest now is only practiced in the wild, I'm afraid; there the slowest, weakest wolf gets the leftovers of the weakest elk, and doesn't stand a chance of getting near a breedable female. Passing along genes is reserved for those at the pinnacle of the hierarchy. Responsible breeders today must do something else do copy Nature, and that is to select breeding animals on the basis of genetic quality as measured by such yardsticks as joint congruity.
In the 1960s, growing out of the observations of past decades' pioneers like Gerry Schnelle, the Orthopedic Foundation for Animals (OFA) was founded. The use of radiographs to see defects and details in the hips of dysplastic and normal dogs proved a boon to the serious efforts of the better breeders. About the same time, the SV (GSD Club in Germany) was using Schnelle's foundation stones to erect an edifice that would eventually deny registration rights to dogs with severe HD (unfortunately they never outlawed the moderate and mild cases from breeding). In East Germany and other Iron Curtain countries, where working ability and health were at a premium and money was not to be wasted (except secretly by party officials), faster progress was made by more restrictive breeding, of only those with the best hips (and bitework).
In the U.S., the categories of relative hip joint tightness (and other features) changed somewhat over the years, until more recently when we have three grades of “OFA-certifiable normal” hips: excellent, good, and fair. The OFA also classifies borderline, mild, moderate, and severe HD. The best progress in percentage of normal offspring (if relying only on OFA data) had been seen in the mating of “excellent” to “excellent,” then “good” x “excellent,” and so on. In recent years more and more fanciers have concluded that “fair” is not worth any more than is “mild HD” as a criterion for breeding, and even “good” is questionable at least half the time. Most of OFA’s evaluations are based on laxity, although any DJD (degenerative joint disease, arthritic bony “calcium deposit” changes) obviously categorize the dog as being dysplastic. The big problem with the old hip-extended-view registries is that this position does not uncover most of the cases of covert laxity. That is, laxity that is there but not demonstrated due to the positioning of the dog being radiographed. In the Shiba, without intensive hunting, endurance, or 18-24-hour herding days to weed out the problem hips, we have seen almost the same incidence as in the larger Akita. That the smaller breeds can more easily shift weight to their front ends and put fewer propulsion demands on their rears, has not made the defect go away, either.
Two movements arose in the past that promised better progress than given by adherence to OFA numbers as the way to coxofemoral nirvana. One was the late and sorely missed Center for Genetic Disease Control (GDC), an organization which had laudably focused our attention on the elbow dysplasias that are big problems in some breeds, nagging ones in others. The other is PennHIP (University of Pennsylvania Veterinary School Hip Improvement Program). I had the pleasure of working with the OFA's first “program director,” Dr. Wayne Riser of the U. of Penn., when I was researching and preparing my book, Canine Hip Dysplasia; I also had the good fortune to visit Dr. Gail Smith (PennHIP) in Philadelphia around 1990, and was a special guest and participant at some of their seminars some years later. I reviewed his methods, philosophy, and results, and became increasingly a supporter of this protocol. My 40+ years of experience with “wedge” radiography, palpation, and follow-up OFA (AVMA) radiographs had convinced me that joint laxity is by far the leading indicator of incipient dysplasia, and that early diagnoses or pre-diagnostic predictors were not only possible but entirely feasible. For practical purposes, in most breeds, you could say that laxity is dysplasia. Good statistical evidence has been developed to prove that vets using the PennHIP-licensed methodology and system can detect the signs of future dysplasia and degenerative joint disease (arthritis) at a pup's early age. Early enough to cull it or them from the breeding programs, start over with better stock, choose better partners, and improve the general welfare of their chosen breed. Or at least the more responsible of the breeding publics will do this.
What PennHIP offers are younger ages at which to identify the most likely carriers of the most bad (or good) genes, a more quantitative (numerical index) evaluation, a more natural positioning of the dog, and faster progress in reducing the incidence of HD. This is no Topsy who arrives on the scene “full-growed, not born,” nor a sudden discovery like that of penicillin, but the result of building “line upon line, precept upon precept.” It has its roots in the fulcrum method I practiced in the 1960s and '70s, in various attempts to position the patient more closely similar to the stance in which weight and stresses are put on the joints, and in the Bardens-Ortolani concept of palpation to discover covert laxity in young puppies. Statistics prove very good reliability in radiographically predicting which pups are at greatest risk of developing DJD (secondary degenerative joint disease), even to as young as four months. The evidence is far too great to fit in this article, but I refer you to my other articles carried on a number of websites such as this one you are now reading.
My logical, skeptical, analytical bent leads me to favor the position utilized in PennHIP, that of a dog that looks like it is standing, but the picture is upside-down. I had tried for a long time to devise a means of radiographing the dog while it was awake and standing, but the difficulties included keeping the dog from moving, and placing a film cassette between its thighs and getting the shadow of its hips exposed while at the same time not having the dog stand spread-eagled. I knew that the extended-leg AVMA standard-view position used by OFA actually “wound up” the joint capsule, tightening the ligaments around the hip socket, when the dog was in that ventro-dorsal mode on its back on the table; that the position tended to show a false tightness of the soft tissues, driving the femoral head into the socket and making it look like a deeper seat. My own recourse for years was the wedge, a can or firm roll placed between the femurs while the hocks were pressed toward one another, in a leverage action that enabled us to pull loosely-held heads out of the sockets. This was fairly good in pups from four to about twenty or so months, but had a few minor drawbacks, one being the adherence to the old paradigm of the human-like extended-leg position. The PennHIP method first seats the heads of the femurs in the acetabula by pressing them in from the “outside” (laterally). Then, while still in the knees-up position and still under anesthesia, the distraction force is applied medially to push the femurs apart and reveal latent or otherwise hidden looseness. Measurements of joint space in both views are made, and a ratio reported (Distraction Index, DI). A threshold level of 0.3 (30% of the way from no space to “horrible”) is probably the best “feel-good” floor for the serious breeder, though other aspects must be factored in, such as size of the gene pool (as in a rare breed), or scarce but extremely valuable characteristics such as hunting ability, health, or temperament. The ideal is to breed dogs with less than, or close to, that apparent threshold DI, or at least to breed your DJD-free dog to a partner with a better DI.
A breed with very few representatives, such as is the case with the Iceland native breed, might have to accept a slightly slower rate of progress (through less stringent initial joint laxity/congruity requirements) until the other desirable characteristics are assured of survival. After all, you wouldn't want to end up with all the dogs in a breed missing half their teeth just because in the beginning of the program those with the best hips also had such mouths. In the case of a populous breed like the German Shepherd Dog, the critical genetic diversity is not really easy because of heavy linebreeding. In America it has been one or two names; in Germany it's been about half a dozen, for the most part. Several years ago Dalmatian breeders had the opportunity to rid their breed of a widespread genetic defect by simply adding a sprinkling of Pointers (these breeds are very close in origin, anyway) and following that with blood testing and elimination of carriers. They rebelled against the idea, even though there would not have been any change in the appearance of future Dals. Today this breed is one of the worst in regard to health problems. It was a “simple” trait, governed by one or two alleles (genes). While the Shiba still is plagued with missing teeth, thanks to judges who don’t pay attention to the Standard’s disqualifications and warnings, the problem is less than it once was.
But the HD problem has not improved noticeably, and that’s where PennHIP holds the greatest promise for the next several decades until DNA-gene markers might be developed. The Shiba has plenty of individuals and genetic diversity to bear up easily under selection pressures designed to truly effectively reduce HD incidence. One reason this is true is the hard work I had done in convincing the AKC to accept the JKC stud book so the gene pool would not be disastrously limited the way it was when the AKC closed it after only a few individuals had been imported. Genetic diversity is very important, but that’s a topic for a different soapbox. HD, also known as CHD in veterinary circles to acknowledge that other species have it, is a polygenic trait (governed by many genes) and therefore much more difficult to weed out. In addition, HD is not the only problem in many breeds. While genetic diversity may be the only or best way to improve on the health and structure problems we have in both imports and more “American” lines, there is another answer or approach to the HD problem. That is: a more stringent criterion for selection of breeding partners, a criterion based on better diagnosis of hip joint laxity than many have been used to for the past 40+ years. After thousands of evaluations in their first years, the PennHIP database developed more than sufficient evidence and logic-based conclusions on which to decide what you should do. The picture is clearly developed in favor of looking for a PennHIP-certified practitioner before you breed those dogs.
Although PennHIP momentum is building in most of the breeds historically associated with HD, it is slower to get off the ground in smaller breeds. Hence the subject of this particular article. HD exists in all breeds, with some such as the racing Greyhound being practically 100% risk-free, others being at grave risk, and most somewhere in between. Small-breed owners often don’t think much about a Poodle that skips because of patella luxation (slipped kneecaps), or a Chihuahua with mild Legg-Perthes, or a Shiba with HD because they can almost get around on their front legs. The PennHIP evaluation device used to spread the femurs apart and demonstrate the otherwise undetectable or lesser-degree laxity is a unit with movable bars in a frame shaped like the letter H or Roman numeral I, but a double line in the middle portion. Most PennHIP vets only have the size distractor used on medium and large dogs, but that might be large enough for a breed the size of the Icelandic Sheepdog, perhaps the larger Shibas, and similar-size dogs. It is currently hard to find anyone who can do the evaluation on a dog smaller than a good-size Shiba but the smaller-size equipment is gradually becoming more widely available. If your dog is not too petite, you might be able to get a good enough radiograph with the standard size unit. Consult one or more PennHIP-certified vets; phone them with your dog’s height and weight and see what the doctors say. To find a list of P-H vets (yes, they must go through training and get certified in order to do this procedure), go to www.pennhip.org/ and then scroll down left side (or across the top) until you find “Locate a vet” & click on it. Or perhaps you can go directly to: http://research.vet.upenn.edu/pennhip/LocateaPennHIPVet/tabid/3539/Default.aspx
One of the films made during the PennHIP evaluation is the extended-leg view, very useful in looking for bony exostoses and remodeling. To keep OFA records, if desirable, the vet can put an extra film into the cassette when taking that shot, and this extra can be sent to OFA for their categorizing. However, there is no added benefit to the extra cost of an OFA number except in a decreasing market where advertising it would have value; besides, PennHIP can be as accurate as young as four or five months.
The more information you have, the better your choices will be. The more information of a precise and accurate nature you have, the faster the progress that you can make in your kennel and breed. Therein lies the great value of the PennHIP method, and it is not merely serendipity that “improvement is their middle name.”
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