What is it?
Legg-Calve-Perthes Disease, also known as Legg-Perthes,
is caused by the disruption of the blood supply to the head of the femur (the
round bone which fits into the hip socket). Legg-Calve-Perthes results when the
blood supply to the femoral head is interrupted, resulting in the death of bone
cells. This is usually followed by a period of revascularization, where the
femoral head is subject to remodeling and/or collapse, creating an irregular fit
into the hip socket. This process of bone cells dying and chipping followed by
new bone growth and the remodeling of the femoral head and neck, leads to
stiffness and pain in the rear leg or legs.
What causes it?
In some cases, trauma, such as a twisting injury
or fracture, can be the initiating factor. Other speculative predisposing causes
can be inflammation, nutritional factors, hip dysplasia, circulatory problems
and possible excessive hormones. Although no specific causes of the disease are
known, it is generally believed to have a genetic mode of inheritance, and is
not believe to be caused by trauma alone. Because there is a genetic component,
it is recommended that dogs affected with Legg-Perthes not be used in breeding
programs. It is considered a polygenic trait in several small breeds of dogs.
Onset can occur from three to eleven months of age.
What are the symptoms?
The young dog will begin to favor one hind leg,
or will walk or limp with a stilted gait. In the rare cases where both hips are
affected, the dog will sometimes "bunny-hop". As the disease
progresses, the dog may suspend the affected limb in the air, and may or may not
exhibit pain when the leg is flexed. In very mild cases, often no symptoms are
apparent, while in severe cases; the dog can be in great pain and become very
irritable.
How is it diagnosed?
Diagnosis is accomplished through radiographs
(X-rays) of the hips, often done under light anesthesia.
What is the treatment?
Current veterinary thinking is that a general
rule of thumb is to allow non-surgical therapy, limiting activity and treatment
with non-steroidal anti-inflammatory drugs for one month. In severe cases, the
dog may become totally lame and avoid use of the affected leg. Furthermore, the
leg muscles may begin to atrophy after extended periods of non-use. If a good
response is not seen, surgical repair by excising the head of the femur should
be considered. By removing the femoral head and neck, the bone on bone contact
that is the source of pain and discomfort is eliminated. Within two months of
surgery, a false joint of scar tissue will form by muscle and tissue, and the
dog may again walk without pain.
What is the prognosis?
Usually excellent, and within several months, the
dog can again walk and run. In some cases, the affected leg may remain slightly
shorter and the muscles may be somewhat atrophied. Some veterinarians feel there
may be an increased risk of arthritis as the dog ages.
What can Westie owners do?
If you have an affected dog, keep records, do not
breed your dog and inform the breeder of your dog. Communicate with other Westie
owners and breeders and with your veterinarian, for possible information about
future research into this disease. Contact can also be made with the Orthopedic
Foundation for Animals, (573)
442-0418, for any updated research information.
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