Testing for hip dysplasia in dogs

Hip dysplasia is a hereditary health condition that leads to abnormal hip development in affected dogs, which can be both painful and affect their normal movement. Because the condition is passed on from the parent dogs to their young, preventing dogs with bad hips from breeding is important, and in some cases, mandated by The Kennel Club for registered pedigree dogs of certain breeds.

Affected dogs may need a fairly complicated surgery to correct the condition, and this is not possible in all cases. This means that by far the best way to manage the general issue of hip dysplasia in dogs is by testing for the condition in potential stud dogs, and ensuring that any dogs affected by it or carrying the appropriate markers for the condition are not used for breeding.

In this article, we will look at hip dysplasia testing in more detail including what it involved, how it works, and how to interpret the results of the tests. Read on to learn more.

What is hip dysplasia?

Hip dysplasia can affect either one or both hips, and occurs when the hips do not develop properly as the dog goes through the transition from puppy to adult, which means that in some cases, the condition will not become apparent until the dog reaches two years of age.

In healthy hips, the ball and socket joints are well matched and fit together snugly, allowing the dog to have a normal range of movement without problems-however, hip dysplasia occurs when these joints develop abnormally, so that the ball and socket joints do not fit perfectly together. This is often exacerbated by poor muscle tone around the hip joint itself, which also helps to keep the joint in place in healthy dogs.

Affected dogs are born with apparently normal hips that do not cause any problems until they get a little older, but over time the ball and socket joint of affected dogs will begin to separate, causing the hips to become malformed, painful, and unable to move properly. This is known as subluxation.

You can find out more about hip dysplasia in dogs in detail by reading this article.

Testing for hip dysplasia

The test required to identify a predisposition to hip dysplasia is called hip scoring, and ultimately results in the person assessing the state of a given dog’s hips assigning a “score” to them, which indicates how healthy or otherwise they are.

The scoring system runs from zero up to 106, and the lower the score, the better the hip health of the dog in question.

Each breed of dog is also assigned a breed average hip score, which can vary considerably between breeds, and umbrella guidance for breeding is to only breed from dogs whose hip score comes in below the breed average.

Scoring is carried out by the professional examination of X rays of the dog’s hips, and these X rays are usually taken at your local veterinary clinic, and then sent off for assessment.

What type of dogs are prone to hip dysplasia?

As the most common hereditary skeletal condition that can affect dogs, a great number of different dog breeds are potentially at risk of the condition. You can search for the risk factors and recommended health tests for your own breed of dog by using The Kennel Club’s Breed Information Centre search tool.

Large and giant dog breeds such as the German Shepherd and St. Bernard tend to be at greater risk of the condition than small and light dogs, but it can present in any breed or type of dog, including cross breeds.

What sort of dogs should be tested for the condition?

If your dog breed has hip dysplasia listed as one of the at-risk condition in The Kennel Club’s database, pedigree dogs of the breed should be tested under the KC/BVA scheme prior to breeding. For some dog breeds that are at particularly high risk of the condition, this is actually necessary in order to be permitted to register the dog with The Kennel Club.

Dogs who also have a known history of hip dysplasia in their breed line whether or not the dog in question appears healthy should also be tested if you wish to breed from them, regardless of whether or not the condition is considered to be prevalent within that specific breed.

Because scoring for the condition is based on X ray examination and the condition often will not become apparent until the dog is fully grown, hip scoring can only be performed on dogs over two years old, in order to ensure that the test returns a definitive result.

This means that it is the potential parent dogs that need to be hip scored, rather than their future litter-and of course, both the dam and the sire should be tested. However, the hip score results are good for life once determined, and so the test and assessment only needs to be performed once on stud dogs, regardless of how many subsequent litters they produce.

You can find out more about The Kennel Club and the British Veterinary Association’s hip testing scheme, including the cost for the test (exclusive of the cost of the X rays) and the averages across different dog breeds by checking out The Kennel Club’s hip dysplasia information section.