Hip Scoring
In
the days before the dog was domesticated, 'survival of the fittest'
was the main rule. Dogs with serious health problems simply could not
move quickly enough to catch or steal food, and starvation resulted
in death. When man interfered with this natural selection process, it
no-longer mattered if the dog wasn't as quick, or agile as he had
been. The dog may seem to have benefited from us, as we have from
him, but at a price. That price is a disease called hip dysplasia
(HD).
The hip is a 'ball and socket' joint, which means that the
'ball' at the top of the femur (thigh) fits tightly into the 'socket'
of the pelvis. This is such an efficient design, that the joints of
land animals and even some birds are very similar. The joint has a
large, cartilage-covered surface, and this is lubricated by fluid
(synovial or 'joint' fluid) to ensure smooth, economical, pain-free
action. When things go wrong with this efficient design, the dog is
described as having hip dysplasia.
This term covers a number of
developmental and other abnormalities of the hip joint. The
developmental changes (primary changes) occur first, and are mainly
growth related. The changes that follow (secondary changes) are
related to wear and tear from usage of the defective joints. This all
results in one or both joints being unable to function properly, as
they are no longer mechanically sound. This usually (though not
always) means the dog is lame, as the unsound joints are painful.
Some dogs (like people) have a better pain-threshold than others, and
as the pain tends to be constant, the dog may not show discomfort by
yelping, as he would if the pain was sudden. This is why dogs can't
be assessed as being free from HD without x-rays and hip scoring.
This is the only accurate way, as it shows the position of the ball
of the joint in relation to the socket, and also shows any secondary
changes, if present.
The scheme was developed in 1965, by the
British Veterinary Association and the Kennel Club, and at the moment
is the most reliable method we have of checking a dog's hip
status.
Because HD is defined as a 'polygenetic trait', meaning
that there is more than one gene involved in producing the disease,
it is not always predictable. It is also affected by environmental
factors i.e. all the outside influences such as diet and exercise, to
name but two. This is why dogs with good hips don't always produce
these good scores in their progeny (offspring) and why we should also
take account of progeny scores when planning a mating.
Apologies
for the poor quality of these pictures, but this is what a good hip
joint should look like. Both show scores of 0 (perfect, no hip
dysplasia).
a) shows radiographic image (x-ray). b) shows line
diagram of anatomical landmarks evaluated during the scoring
procedure.
If
you haven't seen a hip scoring sheet, you've probably never heard of
these technical terms. Each part is checked and given a score, and
these scores are added up to give a total for each hip. The lower the
score, the better the hip, with 0 being a perfect score and 53
(single hip) being severely dysplastic, the worst score possible. The
two scores (one for each hip) are then quite often totalled together
to give a final score.
There are two very informative leaflets on
HD, both available from the B.V.A. (British Veterinary Association,
Canine Health Schemes, 7 Mansfield Street, London, W1M 0AT, Tel 0171
636 6541). The first is 'Hip dysplasia in dogs' written by John
Fisher, and is a basic guide for dog owners. The second, 'The BVA/KC
scoring scheme for control of hip dysplasia: interpretation of
criteria' is more advanced, but very good, especially for people who
do use the scheme.
Unfortunately, this scheme has its
restrictions, the main one being that you can't score the dog 'til
it's 12 months old, and by this time it may have become a much loved
family pet, or successful show dog. The second is that according to
American research, the way we position the dogs for scoring doesn't
give a true picture. They have pioneered a new way of x-raying that
appears to give more accurate results, and can be used much earlier.
The main reason that it isn't available in this country is that there
needs to be some-one present to position the dog while the x-ray is
being taken, which is not allowed in this country.
For more information on this new scheme, called the PennHIP scheme, there is a very good article written by Fred Lanting, THE non-veterinary expert on hips, and author of "Canine Hip Dysplasia" and "The Total GSD". As its on the 'Inkabijou' GSD site, don't forget to return to this site. More info on PennHIP
Another excellent source of information on the disease is the book "The German Shepherd Dog, A Genetic History of the Breed", by Dr. Malcolm B. Willis, the breed geneticist in this country
