HIP DYSPLASIA
Canine Hip Dysplasia is the most common orthopaedic problem seen in dogs and is known to be party governed by genetic factors. It is particularly problematic in large and giant breeds. The system most commonly used in Australia for hip dysplasia "scoring" involves assessing hip radiographs (X-rays) on the basis of 9 criteria. The assessment is done for each hip individually (right and left) and a score of between 0 and 6 is assigned against each of 8 of the criteria and a score of
between 0 and 5 is assigned to the 9th criteria. On this basis the maximum total "score" for each hip is 53. Ideally the scores should be as low as possible and the individual scores for both the right and left hip should be as even as possible. For example, 5:5 is preferable to 1:9 even though in both cases the total is 10.
It is proposed that when an individual hip score (right or left) is > 10, this indicates either gross instability or is a clear indicator of marked hip dysplasia.
A recently published article by the British Veterinary Association (BVA) in "In Practice, April 2012, Volume 34" provides the following information about the interpretation of Total Scores (right and left hip scores added together):
0-4 Perfect or near perfect hips
5-10 Borderline changes that are unlikely to worsen with age
11-20 Mild changes that may worsen with age, sometimes developing into osteoarthritis
21-50. Moderate to marked hip dysplasia in which osteoarthritis is already a prominent feature
>50. Severe to very severe osteoarthritis secondary to hip dysplasia
If the scores of the right and left hips are markedly different, the worse of the two should be considered to be more representative of the dogs hip status. Doubling that single hip score will give a more realistic overall score for purposes of selection for breeding. For example, a dog with a score of 12:3 should be considered to have a hip status similar to other dogs with a total score in the mid 20's.
One of the dilemmas with respect to the interpretation of hip scores is the comparison of an individual dogs hip scores with what is often referred to as the "breed average". The reality is that an average is only relevant in the context of an entire population. Given that not all Labradors are scored and given not all X-rays that are done are submitted for scoring, the so-called "average" is based on a sample and not the entire population. It is therefore better described as a "median" and not an average. Ideally an individual dogs score should be less than the median. The Labrador breed median is currently sitting around 12-13. Were all dogs X-rayed and all X-rays submitted for assessment, however, I suspect the average would be considerably higher.
A dog that is genetically prone to hip dysplasia may be prevented from having severe problems by controlling their diet. Equally, a dog that is not genetically prone to hip dysplasia can develop it if not fed properly in the initial months of its life. Exercise can also play an important part.
PLEASE NOTE ALL REGISTERED BREEDERS MUST SUBMIT HIP AND ELBOW SCORES FOR BOTH
SIRE AND DAM PRIOR TO LITTER REGISTRATION.
For further information on the scoring system detailed above please refer to the following sites:
www.research.vet.upenn.du
www.online-vets.com/hipscore_1.html
www.bva.co.uk/public/documents
Canine Hip Dysplasia is the most common orthopaedic problem seen in dogs and is known to be party governed by genetic factors. It is particularly problematic in large and giant breeds. The system most commonly used in Australia for hip dysplasia "scoring" involves assessing hip radiographs (X-rays) on the basis of 9 criteria. The assessment is done for each hip individually (right and left) and a score of between 0 and 6 is assigned against each of 8 of the criteria and a score of
between 0 and 5 is assigned to the 9th criteria. On this basis the maximum total "score" for each hip is 53. Ideally the scores should be as low as possible and the individual scores for both the right and left hip should be as even as possible. For example, 5:5 is preferable to 1:9 even though in both cases the total is 10.
It is proposed that when an individual hip score (right or left) is > 10, this indicates either gross instability or is a clear indicator of marked hip dysplasia.
A recently published article by the British Veterinary Association (BVA) in "In Practice, April 2012, Volume 34" provides the following information about the interpretation of Total Scores (right and left hip scores added together):
0-4 Perfect or near perfect hips
5-10 Borderline changes that are unlikely to worsen with age
11-20 Mild changes that may worsen with age, sometimes developing into osteoarthritis
21-50. Moderate to marked hip dysplasia in which osteoarthritis is already a prominent feature
>50. Severe to very severe osteoarthritis secondary to hip dysplasia
If the scores of the right and left hips are markedly different, the worse of the two should be considered to be more representative of the dogs hip status. Doubling that single hip score will give a more realistic overall score for purposes of selection for breeding. For example, a dog with a score of 12:3 should be considered to have a hip status similar to other dogs with a total score in the mid 20's.
One of the dilemmas with respect to the interpretation of hip scores is the comparison of an individual dogs hip scores with what is often referred to as the "breed average". The reality is that an average is only relevant in the context of an entire population. Given that not all Labradors are scored and given not all X-rays that are done are submitted for scoring, the so-called "average" is based on a sample and not the entire population. It is therefore better described as a "median" and not an average. Ideally an individual dogs score should be less than the median. The Labrador breed median is currently sitting around 12-13. Were all dogs X-rayed and all X-rays submitted for assessment, however, I suspect the average would be considerably higher.
A dog that is genetically prone to hip dysplasia may be prevented from having severe problems by controlling their diet. Equally, a dog that is not genetically prone to hip dysplasia can develop it if not fed properly in the initial months of its life. Exercise can also play an important part.
PLEASE NOTE ALL REGISTERED BREEDERS MUST SUBMIT HIP AND ELBOW SCORES FOR BOTH
SIRE AND DAM PRIOR TO LITTER REGISTRATION.
For further information on the scoring system detailed above please refer to the following sites:
www.research.vet.upenn.du
www.online-vets.com/hipscore_1.html
www.bva.co.uk/public/documents