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Cause
of HD — A Summary |
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. There is an article floating around, proclaiming that Hip Dysplasia is NOT genetic, but that it's
primary cause is dog food and the environment. |
There will always be those who rebel against evidence, and pick a
seeming exception on which to build a contrarian
theory. It’s like the cults that take a verse of the Bible, misinterpret or
mistranslate it, and build a whole religion on it. They balance an Egyptian
pyramid upside-down on its pointed head. Eventually such a structure will fall.
The
bane of the scientist has always been the multitude of anecdotal reports that,
like mushrooms, pop up suddenly and unexpectedly in the dark. One such report
(without scientific controls) from Norway in the early 1990s argued that in
five breeds, but not two others, HD was more likely to show up in puppies that
grew up in the fall and winter. As in other amateur observations, questions
were raised regarding exercise and sunlight (vitamin D) among other
differences. In fact, most attempts to pin the blame of HD onto environment
involve diet and exercise. While we must not reject out of hand all anecdotal
claims, we must also place our bets on the repeatable, controlled studies, if
we want to gain true knowledge. People have blamed the brand of dog food, the
footing puppies were raised on, and other things for the appearance of dysplasia in puppies that they have sold, with or without
guarantees and/or stipulations. There is no scientific basis for these excuses
people use in order to not make good on defective “products”.
On
the other hand, there is plenty of support for the fact that “overnutrition” and more rapid growth are responsible for
the genetically pre-disposed dog to develop worse and earlier HD than might be
the case if on a restricted diet. My new revision of the HD book will deal with
this in detail. While some have claimed that exercise is needed to maintain a
“deep acetabulum”, there is likewise no controlled
study to back up this concept. It is “common wisdom” that hip-extended
radiographs seem to show less laxity in young dogs that have been kept lean and
frequently exercised, such as in training for schutzhund
and police work, than found in dogs living a more relaxed life, but stress
radiography shows every case of laxity. Muscle tone can have some positive
effect on the tightness of the joint capsule, as long as regular exercise is
maintained. It has no effect, however, on the genes, so a dog that has been
“lean and mean” until its skeleton had fully ossified, is just as dangerous to
breed to as is his littermate who has reclined on a couch most of his
growing-up life.
GENES, NUTRITION, AND
DENIAL
At the
end of Year 2000, an article appeared in the underground media, primarily
Internet and e-mail discussion groups, called “The Error of the Millennium in
Veterinary Medicine”, a sequel to a “compendium” pamphlet called “The Thirty
Years’ War”. The reason it was there but was refused by all legitimate journals
and magazines was that its premise was so preposterous. It reminded me of the
inflammatory claim of the same decade that the Nazi Holocaust never happened.
Of course, history is full of examples of error that promenade as fact, and
discoveries that are suppressed for long years until someone else proves their
validity. For one, an Australian researcher named Barry Marshall stated that
stomach ulcers were caused by bacteria, and even proved it by swallowing the
microbes, developing ulcers, and curing them with antibiotics. Yet the
textbooks for years continued to give the “risk factors” as smoking, alcohol,
stress, and genes. We now know that TB and peptic ulcers are infectious
disorders, as the
But
the exception does not become the rule. A lot of error can be cloaked in a very
little truth, and if viewers want to see only the flashy ornamentation,
then that’s all they will see. The authors of the current heresy that HD
is not genetic, but is caused by nutrition, make at least as many false claims
as did the purveyor of ascorbate as a preventative
and cure for dysplasia. While doing so, they
hypothesize (or fabricate, really) a monstrous conspiracy drama in which the
villains are “the dog breeding associations in the United States, United
Kingdom, France, and Germany [that] developed X-ray systems”. They claim that
attempts to eliminate HD through selective breeding “proved fruitless” for
three decades, and they make the illogical conclusion that this is the reason
the incidence “persists at around 60-65%”. Quoting themselves in their book, a
vet named Torel and a journalist named Kammerer make amazing far-out statements such as “breeding
programs… cannot hope to bring about any fundamental improvements …because CHD
is not heritable and existing dog food… is in fact the original cause of
CHD.”
How
ridiculous this is, can quickly become clear by asking yourself
why the dogs I and countless others have bred selectively for good hips
are not ruined in spite of lavish helpings or restricted diets (doesn’t
matter). Why do Greyhounds not get HD, when they eat the same rations that Clumber
Spaniels do? Why are some of us who use selective
breeding successful, while those who do not, have multiple failures, and
yet we all feed basically the same commercial preparations?
The
conspiracy theory includes accusations that the national all-breed club in
SUMMARY
The
base cause of HD and other orthopedic diseases is a
collection of enough genes that act together to bring on the condition and the
signs. Since it is extremely expensive and difficult to find specific genes,
even in this day of genome mapping, it is more convenient, when speaking of the
“causes”, etiology, or pathogenesis (they all mean
much the same thing), to focus on the secondary causes. These may
include development of a deep or shallow acetabulum,
weak musculature and ligaments, speed of growth of bones vs. muscles, synovial
fluid aberrations, and other
features which might be identified early, but remember that all these have
their own “bad genes”. No matter how much research into the role of those
factors you support, you must still practice good genetics if you wish to make
progress in your own kennel or breed. Dr.
Lust of Cornell, for example, says flat out “Canine hip dysplasia is a
hereditary disease”. All of the best work of hundreds of dedicated scientists
in a score of countries is summed up in that simple, concise statement of
truth. Unadorned, forceful, and direct, this says it all.
Note:
Fred Lanting, author of the book on HD and
worldwide lecturer on the subject, is working on a greatly expanded version of
the book. Start saving up your money now. There is not
another that is or could be anything like it. It is the product of 35 years of
intensive research and experience in the field. Watch for announcements.
