Canine Hip Dysplasia

Canine hip dysplasia can affect all dog breeds;
however, German shepherds and other large
breeds are most commonly affected clinically.
Hip dysplasia is a genetic disease which is
related to the degree of looseness of the hip
joint, also known as hip laxity. Laxity in the
ball-and-socket joint over time results in
damage and remodeling of the surfaces which
contact each other. These changes are often
not visible on X-rays until two years of age or
older. Thus, before it shows any clinical signs,
a young diseased animal can pass on the
inherited trait to its offspring.

Fortunately, a new technique is available to
determine hip laxity in younger animals. This
technique, called PennHip®, measures laxity
in hip X-rays using a special device called a
distractor. The distraction index is a
measurement calculated from the X-rays. The
distraction index is a measure of passive hip
laxity expressed between 0 and 1. A distraction
index of 0 indicates no joint laxity and very tight
hips, whereas a distraction index of 1 indicates
very loose hips. Each measurement is entered
into a worldwide, breed-specific database
which allows for comparison of individual
scores.

The PennHip® technique is being embraced
by conscientious breeders to target diseased
animals before they are bred. The technique
can be done in animals as young as four
months, compared to conventional methods of
diagnosis (OFA) which cannot be done until
two years of age. The aim of the PennHip®
program is to decrease the prevalence of hip
dysplasia in all breeds by helping breeders
select the best dogs to breed. PennHip® is
also a benefit to individual pet owners, by
allowing you to identify your pet’s susceptibility
to develop hip dysplasia. This allows you and
your veterinarian to plan lifestyle adjustments
to minimize the chances of clinical disease.

What can you do to help decrease the
prevalence of hip dysplasia? Before you buy a
purebred dog, ask dog breeders what they are
doing to screen their breeding animals for hip
dysplasia; especially breeders of predisposed
breeds (German shepherds, retrievers). If you
have any questions about treatment and
prevention of hip dysplasia, your veterinarian.