[This material 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.]
1. Select the very best dogs (companion, working
dog, or foundation stock) you can find.
2. Use the most accurate and advanced diagnostic
techniques available and economically feasible.
3. Base breeding decisions partly on progeny results;
one tool in that category is BV or ZW (Breeding Value
or Zuchtwert).
4. Favor open registries; these are those in which
the "failures" as well as the dogs with better
hips are identified publicly.
We might as well consider these items in the order summarized
above. Whether you intend to breed dogs or not, number 1 is
very important. You and/or your puppy customers certainly
would not purposely select defective dogs, but in effect,
not selecting against a problem can be thought of as selecting
for it. Think of the analogy in training. If you do not train
for correct behavior, you are actually "training"
incorrect behavior. Picking a dog to share your life, home,
and time could be a ten-year or longer investment. Besides
the features of temperament, size, coat, general health, and
so many more, you owe it to yourself and the dog to choose
an animal that has good odds of having serviceable hips and
other joints. Back in dogdom's dark ages, longevity of ancestors,
ability of parents and the individual to work long hours without
pain or perform certain utilitarian functions were all that
owners could use. In the 1950s and `60s, realization that
hip dysplasia could often be detected with radiography, and
that it was an identifiable genetic disorder, led to the establishment
of many hip detection and registration schemes around the
world. In the U.S. (and serving much of Canada's needs), the
Orthopedic Foundation for Animals was established at the U.
of PA, with Wayne Riser at the helm. Breeders now had a standardized
means of listing potentially valuable breeding animals that
had no evidence of severe or moderate hip dysplasia. This
was a definite advance over the performance tests, giving
more information on this specific portion of a dog's phenotype.
Dogs that were considered "normal for age and breed"
were given a certification number, and as time went on, people
could fairly safely assume that a dog without this certification
were dysplastic. The certificate thus became a valuable commodity.
It marked dogs as more valuable than similar dogs without
it. Unfortunately, the inertia that came with great numbers
of dogs in the OFA registry may have contributed toward an
unwillingness to consider technological improvements. After
30-some years of service to breeders, this stagnation and
protection of the old method had left breeders on a plateau
without offering any ladder to the next level of progress.
It was time to examine new paradigms.
That much-needed route to the next pinnacle also came out of
the U. of PA (called "Penn"). By the early 1990s,
research had already established an improved diagnostic or
predictive technique that promises great benefits to those
who want to produce or buy sounder dogs. As Solomon said,
there is nothing truly new under the sun, but there can be
advances and better combinations or arrangements of data or
genes or methods than what has been seen before. The better
method, given the acronym PennHIP® for (University of)
Pennsylvania Hip Improvement Program, was not entirely new,
but was based on the concept suggested by earlier experiments
in puppy palpation, "wedge" radiography, and other
positions utilizing stress to push femurs apart and demonstrate
joint laxity that was hidden in the older views. It is a more
highly refined approach, standardized for accuracy and repeatability,
and is more quantitative than the almost entirely subjective
OFA or hip-extended approaches. While the older position with
the dog's legs stretched out as if resembling those of a bipedal
human lying supine on the table is best for identifying mineralization
("calcium deposits" and arthritis) in the hip joint,
it allows too much covert laxity to be a reliable indicator
of things to come. Since in many or perhaps most cases a loose
hip will develop degenerative joint disease (DJD), it is wise
to detect as much laxity as possible and compare it with numerical,
measurable standards of excellence and risk. The looser the
joint, the higher that risk of the dog's eventually getting
DJD, regardless of breed. Website articles that treat the
differences between PennHIP and older methods in more detail
include those on <http://realgsd.net/GSDinfo/News/FredL/1fredlanting.htm>,
<www.synbiotics.com>, and <www.vet.upenn.edu/researchcenters/pennhip/>.
One of the important advantages of the PennHIP stress-radiography
method is that it allows accurate and much earlier prediction
of an individual dog's later hip status; it is a vastly improved
estimate of risk for developing DJD. And the scientific data
is more than sufficient to be a convincing case for breeders
to use PennHIP. As I have said in another place, 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.
The use of Breed Value (progeny and sibling results being made
part of a dog's likely genetic picture) has not been practiced
much in this country. It is an old, established, and critical
feature of dairy cattle breeding, but in the U.S., only two
groups are known to utilize its very helpful advantages. One
is the breeding program at The Seeing Eye, Inc.®, the
famous school for guide dogs for the blind in Morristown NJ.
The geneticist there, Dr. Eldin Leighton, has used PennHIP
for diagnosis/prediction and BV data on relatives (mostly
siblings, ancestors, and progeny) to make great strides in
reducing HD incidence far below that possible in any other
breeding program. The other is the community of fanciers devoted
to the imported German Shepherd Dog. In Germany, the SV (parent
breed club for all GSDs worldwide) has adopted a very similar
data analysis system called Zuchtwert (breed worthiness).
Through a very complicated formula, the numbers and values
of acceptable and unacceptable hip ratings of siblings and
progeny are calculated. Stud dogs and brood bitches with low
ZW numbers are more desirable as breeding partners and the
parents of a pup you'd want to buy. The average hip quality
of GSD in Germany is fast-normal, meaning "nearly normal",
and the ZW number of 95 correlates to that status in a statistical
way. That is to say, a dog with 95 might not have fast-normal
hips itself, but on average, there is a correlation across
the breed population. A dog whose hip radiographs are superior
will get a lower ZW number than he was born with, which was
the average of his parents' numbers. Furthermore, if he has
previous siblings and half-sibs that have been radiographed,
their results can also move his number one way or the other.
His sire or dam may produce better or worse hips with a different
parent, and that will also affect his official number. For
the non-statistician, it is enough to look for families and
individuals with low numbers, as the higher the number, the
more HD that particular dog has produced or is likely to produce.
The fourth major tool in a successful fight against proliferation
or prevalence of hip dysplasia, or almost any disease for
that matter, is knowledge. This time, knowledge in the form
of open and honest information on the hip status of the dog
you are interested in breeding to or getting a pup out of.
On this side of the oceans, we have only one truly open hip
registry, the GDC, which stands for Institute for Genetic
Disease. This organization is on shaky ground because breeders
are not availing themselves of the benefits that would apply
if they practiced more participation, more sharing of information.
Without sufficient numbers of dogs in the database, the GDC
can do very little to give what could be a better look into
the genotypes of the potential breeding animals. If people
change sufficiently, the GDC can revive; at present, it may
have to act in a more limited manner. One obstacle is the
complacence of the American dog fancier. The typical owner
took a long time to accept OFA or an equivalent registry of
"normal" or "acceptable for breeding"
dogs. To change horses in mid-stream is not something most
would want to attempt, or have the gumption to do even though
it is easy. The other obstacle is the OFA's intransigence
to such matters of progress. They had the opportunity to persuade
their almost-captive clientele to switch to an open registry,
one in which inquirers could get the readings on potential
studs, dams, or near-relatives of their own potential breeding
stock, but the managers gave the inadequate excuse that it
might discourage owners from having dogs radiographed and
entered into the database. They have refused to adopt the
progressive ideas of GDC as they have refused to advance into
the superior stress-radiographic technique developed at Penn.
It is largely a matter of politics. OFA leaders are at personal
odds with those at Penn, and resented the possible threat
of competition from GDC. If cooperation were the word of the
day instead, there would not have been the need for competing
organizations. But the person carrying old, heavy baggage
is going to be passed up by others sprinting for the best
seats on the train. As we "go to press" with this
article, GDC is engaging in more friendly discussions with
OFA. GDC is to be found at <http://www.vetmed.ucdavis.edu/gdc>.
I contend that the wisest breeders and shoppers will use all
the tools they can to improve their breeds and lines. The
ultimate would be to use PennHIP for early risk prediction
and a numerical comparison value, selection of stock with
lower ZW-BV numbers if available, and submission of radiographs
to an open registry (GDC if they still operate that service
for hips). Breed clubs can do much to improve genetic health
by peer pressure through awards and codes of ethics. Unfortunately,
they are not allowed to put restrictions on which dogs are
allowed to breed if they are affiliated with AKC, as that
monolith is in the business of appropriating not only breeds
and breed clubs, but controlling all registration decisions
as well. And their practice has always been to register anything
as long as the money and the form are sent in, and there is
no complaint about it. In other countries, it is the breed
club that is the sole and responsible guardian of the breed.
Here, we must rely on salesmanship and P.R. to mold attitudes
and encourage compliance with common-sense practices such
as those that would improve hip quality.
What about the update on progress mentioned at the outset?
The GDC is floundering, though worthy of support and revival.
The OFA shows no signs of progress. Nor do they supply us
with print information, but direct us to their inadequate
but large website. It does little good, when the hip-extended
method is ambivalent in value or accuracy, to list only dogs
that have "passed" their low or imprecise standards
- what of the other relatives that do not pass? What of progress
at Penn? This is the only one of the three that is moving
at "fast-forward", and much has been published in
the professional (veterinary) literature that supports the
value of the PennHIP technique. Among the latest are two articles
that should appear around the first quarter of 2002 in JAVMA,
the largest and possibly most prestigious and demanding of
the vet journals. One is on risk factors for DJD and its confirmed
relationship to DI. Distraction Index is Penn's numerical
(quantitative) description of how much laxity can be revealed
when a small but significant force is applied to separate
the ball from the socket so that a picture can be taken while
the hip is in this loosest state. Remember, OFA's premise
is also that "tighter is better", although Penn
has the only well-known method of determining true tightness.
Another article will deal with the significance of a line
of extra density, thickening, or mineral deposits on the shoulder
of the femur, first studied by Dr. Joe Morgan at U-Cal.-Davis
and popularly known as "Morgan's line", but in the
new paper referred to as "caudolateral curvilinear osteophyte".
I predict this mouthful will not replace the common moniker.
Whatever it's called, it may be a help to vets who still rely
only on the hip-extended, subjective view.
Not really new, but an update of sorts for newcomers to the
discussions on hip quality analysis, is the fact that PennHIP
radiographs can only be submitted by trained and certified
vets and their certified/trained technicians. Trained by Synbiotics/Penn,
that is, in such symposia-connected sessions as the Feb. 10,
2002 Las Vegas seminar held immediately prior to the Western
Veterinary Conference. Vets who withhold radiographs because,
for example, there is obvious HD or DJD, are dropped from
participation. This protects the integrity of the database
and prevents the type of bias found in OFA, where mostly the
good hip pictures are sent in, and the bad-hip dogs hide in
the shadows. Vets who would allow their non-certified assistants
to do the radiography without their personal action in holding
the distractor or manipulating the dog's legs will also face
expulsion, as has happened twice that I know of. Semi-annual
breed prevalence and statistical profile updates are made
available to participating veterinarians and the Synbiotics
or Penn websites. Penn has made a small move in the direction
of an open registry, leaving the decision up to the breeder/owner
to decide whether to check off the box indicating willingness
to share information. That is a small box, and since an office
worker often fills out the form down to just before the owner's
signature, it is not checked as often as it should be. Make
sure you see and check-mark it when you have your dog evaluated
by a PennHIP practitioner, so others interested in breeding
to your dog or its parents can contact you. If you want to
find out about the DI of a dog or close relatives, you can
network with the owners who allow their names and addresses
to be made available. PennHIP is still a closed registry,
so they will not reveal the DI of dogs, but they advise that
when you contact the owner-participants, you ask for a photocopy
of the official PennHIP report. If not, you could be fooled
by disreputable owners. For example, a dog with considerable
DJD may have its joints so "frozen" by calcium deposits
that much laxity cannot be demonstrated. You also must see
the part of the report that mentions the absence or presence
of remodeling or DJD or evidence of HD. Just to say that a
dog is in the 80th percentile or whatever, in regard to comparative
laxity is not enough. You need all the information on the
report. An owner can get his breed's listing by phoning Synbiotics
at 800-228-4305, and using the phone prompt for "Technical
Services", then asking for "Breeders wishing to
share information".
What is the latest in certain breeds? I am listing here only
those breeds for whose magazines or websites I have previously
written articles. The others will be found on Synbiotics'
website. I'll start with my own favorite breed, the GSD, although
the Golden has one-third more dogs in the database and the
Lab has nearly 80% more. The GSD has a mean DI of 0.43 which
means that you should prefer breeding partners that are not
higher, and especially look for ones toward the 0.3 threshold
below which there is no DJD development. The Shiloh Shepherd,
basically a strain of GSD selected for larger size among other
characteristics, also has a mean of 0.43 (currently now at
0.41) but the King Shepherd, a small splinter or dissident
group from the Shiloh club's original registry, has 0.5 as
their mean DI. This could mean that the breeders and owners
of King Shepherds are more lax than their dog's hips! For
those not familiar with DI, let me suggest that you could
think of a number such as 0.50 as representing a joint in
which distraction allows the ball to be moved about 50% out
of the socket. For a Corgi, Neapolitan Mastiff, or Newfie,
this amount may not be as serious, but for a GSD it is definitely
a situation to be avoided. There are breed differences as
to relationship between laxity (DI) and later DJD.
Airedale Terriers: 0.58, but this is one of those breeds
in which the DJD isn't as bad at that level as it would be,
on average, in the GSD.
American Bulldog: 0.57
American Pit Bull Terrier and American Staffordshire Terrier
(basically the same breed with different registries): 0.59
to 0.61
Australian Shepherd: 0.49
Australian Cattle Dog: 0.56
Canaan Dog: 0.48, which may surprise some who believe
that the rigors of feral life eliminate much HD; in fact,
more depends on a combination of breed/group/family phenotype
in those "wild" breeds that actually do not compete
that much for food and breeding. But the truly wild dogs that
rely on very demanding environments that weed out the weak,
and allow only the strongest to do the breeding in the pack,
are famously low in HD incidence. The wolf in its many varieties,
the Dingo, and even such wolf-domestic dog blends are examples.
The Lupine breed, which is mostly Northern Gray Wolf or Timberwolf,
and the American Tundra Dog which is another wolf blend, do
not have statistically high enough numbers submitted to PennHIP
yet, but so far are quite low in DI and I predict will continue
to be so.
Dutch Shepherd: 0.53 It is interesting to compare this
with its close cousins the Belgian Shepherd varieties - the
black Groenendal has 0.3, the mahogany Tervueren
has 0.35, and the short-coated Malinois has 0.39. The Dutch
Shepherd is phenotypically and probably historically an intermediate
form between the GSD and the Belgian Shepherds.
Mastiff: 0.51 More commonly, perhaps, referred to as
English Mastiff or Old English Mastiff
English Shepherd: 0.62 Also known by some as "Farm
Shepherd", a breed found mostly in the U.S.
Fila Brasileiro: 0.56
Greater Swiss Mountain Dog: 0.56
Neapolitan Mastiff: 0.65
Nova Scotia Duck Tolling Retriever: 0.53
Rottweiler: 0.55 It is of importance and interest that
the typical Rottie with a given DI will usually have less
DJD than a typical GSD with the same DI. There are even greater
differences between several other breeds.
Shiba: 0.52 Compare this with its descendant, the Akita
which has 0.6, but also with breeds more frequently identified
with HD symptoms. Even light-weight, small dogs' hips should
be monitored and improved.
By the way, the Greyhound is listed as having a mean
DI of 0.23, but it was not made clear if this included both
the track and the show Greyhounds. Breeds like this and the
Whippet have nearly a zero incidence of HD, although
occasional examples of dysplastic individuals are seen.
In summary, big advances in the field of hip dysplasia do not
come along frequently, but when they do, there is no excuse
for not availing ourselves of them. The latest "great
new thing" was the introduction of the measurable stress
radiography technique at Penn. Since then, voluminous studies
there and elsewhere have confirmed the superiority of this
radiographic approach over all others in the world. I am not
including such overpriced research methods as MRI, nor do
I foresee any genome maps in the future that will help, partly
because of the polygenic nature of HD. Those who can use the
most tools will have the best chance of success. If you have
friends in countries where there are no PennHIP certified
vets, urge them to use the ZW system where they can, and radiograph
dogs later in life to see if DJD has developed after the usual
age of certification, which frequently happens. If you don't
have BV-ZW available in your breed, use PennHIP even if you
have to travel. Share all your results with the public, whether
flattering or dismal or anywhere in between, for the sake
of the breed and your fellow dog fanciers.
[note: Fred Lanting, aka [email protected],
presents seminars worldwide on orthopedic disorders, gait-&-Structure,
and other topics. He is an SV judge of the GSD, and an international
all-breed judge for several registries. His co-owned website,
managed by another, is www.vonsalix.faithweb.com]
[ Next ]
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.
*******************************
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 terminology. Keep up the good work!
********************************
DISCLAIMER: This information is presented for the educational
and free exchange of ideas and speech in relation to animal's
health and wellness only. It is not intended as a substitute
for the advice and treatment of a licensed professional. I
am NOT a veterinarian and I do NOT provide medical advice.
Please consult your veterinarian for any medical problem.
******************************
If you know of any well written articles or know
about another Holistc/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!