Hip Dysplasia

The Alaskan Malamute, like most large breeds, suffers from a moderate incidence of canine hip dysplasia. To put it in basic terms, hip dysplasia is an imperfect formation of the ball-and-socket assembly in the pelvis. The degree of imperfection can vary, from very slight, which does not visibly affect a dog, to very severe, in which the animal is so badly affected that euthanasia is the only humane course.

Veterinarians and medical researchers are divided in their opinion as to the exact cause of hip dysplasia. Although the mode of inheritance has not been fully determined, it is generally felt to be polygenic in nature with possible influence from environmental conditions.

While much remains unknown about hip dysplasia, it has been conclusively demonstrated that the breeding of dogs with affected hips substantially increases the incidence of hip dysplasia in the puppies. Since such a pattern could, if continued, lead to a large population of affected dogs, it becomes important to restrict breeding stock to those dogs with sound hips. Although a dysplastic puppy can still occur from a mating of clear parents, the chances are much smaller than if one or both parents are themselves dysplastic.

Manifestation of hip dysplasia often begins between the ages of six to twelve months. Symptoms may range from slight difficulty in getting up to actual crippling of the dog. Dysplastic dogs often display a tendency to pace. However it should be noted that not all dysplastic dogs pace, and not all dogs that pace are dysplastic.

Since dogs with hip dysplasia can present a completely normal appearance, another and more conclusive method of detection must be employed. This method is the pelvic radiograph, or x-ray. Such radiographs, taken and evaluated by trained personnel, sustain a high degree of accuracy in dysplasia diagnosis. The x-ray of a dog with normal hips shows a tight fit between the femoral head (ball) and acetabulum (socket). The acetabulum is deep and well-formed, with approximately two-thirds of the femoral head seated within it. The x-ray of a dysplastic dog shows varying degrees of looseness between the femoral head and the acetabulum. The acetabulum is shallow, with only a small portion of the femoral head seated within it. In addition the x-ray may reveal a thickening of the "neck" of the femoral head.

The Orthopedic Foundation for Animals, abbreviated OFA, has established a hip control registry for all breeds. Radiographs submitted to OFA are evaluated by three radiologists. If the consensus diagnosis is clear, a certificate is issued. Minimum age for certification is two years, although radiographs of younger dogs will be read. Many breeders x-ray their dogs at about one year of age and then again between two and three years of age. OFA estimates that radiographic evidence of dysplasia will appear by age two in 95% of all affected dogs. Thus the early x-ray is generally regarded as a preliminary indication, with much more importance being attached to the later x-ray. OFA may be contacted at 2300 East Nifong Blvd., Columbia, Missouri 65201-3856.

When contemplating purchase of a Malamute for breeding stock, you will want to ensure, as best possible, that the dog has sound hips. In buying a dog over one year of age, the hips should be radiographed and read normal by either OFA or a certified radiologist. In buying a puppy, both parents should be cleared by either OFA or a certified radiologist. No breeder can absolutely guarantee that your particular puppy will not be dysplastic, but the reputable breeder, using only clear stock, will give you the best possible chance. It should, however, be clearly understood by both parties, before purchase, what adjustment shall be made in the event the dog is diagnosed as dysplastic.

In spite of the most conscientious efforts, a majority breeders produce a small percentage of dysplastic dogs. These dogs, if not badly affected, can lead normal and happy lives. They should not, however, be used for breeding. Many breeders will place such dogs into homes at a reduced price, on the condition that the animal must be rendered incapable of reproduction.

Hip dysplasia is not an easy subject to understand, and even the most experienced breeders and researchers admit to frustrating gaps in their comprehension. This brochure is a very brief introduction to a very complex subject, but hopefully it will serve to acquaint the prospective Malamute owner with the continuing problem of canine hip dysplasia.

Linda Dowdy
Bethel, Minnesota
Comments or questions? E-mail me at lindowdy@visi.com

Copyright © 2006-2007 Linda Dowdy, last revision 061101