Hip
dysplasia
Download AMCV Hip Dysplasia Policy & Form
What is Hip Dysplasia?
Hip Dysplasia is basically a deformity of the hip joint in which the head of the femur (ball section of the joint) fits poorly into the acetabulum (the socket).
Due to the poor fit of the joint, the ball moves in the socket in an abnormal manner leading to wear and tear on the surfaces of the joint and the development of arthritis. The ligament and capsule around the joint become slack and the muscles of the hindquarters waste away.
Above: Ventro-dorsal x-ray of a dog with good hips
Hip dysplasia is a largely inherited condition seen mostly in the bigger breeds of dogs, such as the Alaskan Malamute, although environmental factors also play a part in the soundness of the hip joint. The mode of inheritance is polygenic, meaning that a number of genes interact to determine the final physical characteristics of the hip joint.
Signs of Hip Dysplasia
The signs of hip dysplasia may develop in a pup as young as 3 - 4 months in age, but may not become apparent until the dog is older. A dog with hip dysplasia may not show any obvious signs initially, however the hips can degenerate with age and the dog may eventually suffer severe pain and difficulty in moving the back legs. Hip dysplasia may be indicated when a dog shows discomfort after exercise, a tendency to "bunny hop" when running, an awkward, rolling movement rather than a smooth gait, difficulty in jumping or getting up from lying down and a reduced level of activity. Hip dysplasia can only be confirmed by hip x-ray when the dog is over 12 months of age.
Prevention
Hip Dysplasia has been diagnosed in more than 100 breeds of dog. Fortunately, studies have shown that the chances of progeny being hip dysplastic are significantly decreased when both parents have normal hips.
The degree of Hip Dysplasia is indicated by a scoring system for each hip, the lower the score, the better the hips. Dogs with hip scores 0 - 7 on either hip are considered to have normal hips and are suitable for breeding, while those with hip scores of greater than 7 on either hip are considered hip dysplastic and are therefore not suitable for breeding. Hip dysplasia can be progressively eliminated by only using dogs with normal hips (as determined by x-ray) for breeding programs. Dogs with hip scores closer to 7 should only be bred with dogs with lower hip scores, e.g. 0 - 4.
It should be remembered that, although both parents may be free of hip dysplasia, there is no guarantee that the progeny will not be hip dysplastic, however the chances of having pups with hip dysplasia will be greatly reduced.
When looking at a litter ask the breeder to see the hip evaluation reports for the sire and dam. A valid report will include:
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the kennel name of the dog which has been x-rayed
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the kennel names of the dog’s parents and grandparents
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a break down of how different aspects of the hip joint were scored
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a final score for each hip based on the cumulative scores
(0 = excellent, 53 = worse possible score). -
the suitability of the dog for breeding based on the hip score obtained for the worst hip.
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the signature of the veterinarian who read the hip x-ray.
Puppy buyers can help reduce the incidence of hip dysplasia in the Alaskan Malamute by seeking breeders who have had both parents hip x-rayed and passed for hip dysplasia. Prospective buyers should check pedigrees and verify health issues with the breeder and, if suitable documentation is not available, assume the worst until proven otherwise.
Normal hip A mildly dysplastic hip
Moderately dysplastic hip A severely dysplastic hip
Hip dysplasia can range from mild to severe
(top right to bottom right)
Produced by The Alaskan Malamute Club, Victoria Inc.
References & further information:
Orthopedic Foundation of America
(OFA) -
www.offa.org/hd_guidelines.html
Introduction to Canine Hip
Dysplasia:
info.antechimagingservices.com/pennhip/navigation/hipDysplasia/introduction.html
Diagnosis and Genetics of Canine Hip Dysplasia
- Baker Institute for Animal Health, Cornell University
Genetic Control of Canine Hip Dysplasia - Kapatkin A.
et al, University of Pennsylvania