BVA/KC Hip Dysplasia Screening Scheme

Hip dysplasia is controlled by a number of different genes and influenced by several environmental factors (e.g. diet, exercise or factors when in the womb before birth etc.). Each of the genes that help to make a dog’s hips may have different possible versions, or variants. Some versions increase the risk of hip dysplasia, while others decrease the risk.

Each dog will have a mix of these “good” and “bad” versions of genes, making it very difficult to predict whether a dog will be affected. The impact one version of a gene has might only be slight, but lots of genes having a small influence have a combined additive effect.

The way in which these conditions are inherited is not straightforward; hence the name complex inherited disorders. These complex diseases are usually seen across many different breeds and are also described in both cross breeds and mixed breeds.

Since hip dysplasia is an inherited condition, dogs that share similar genes are more likely to share similar inherited conditions. Individuals in each breed share a significant amount of their genetic make up and so certain breeds are more vulnerable to hip dysplasia.

It is generally accepted that this condition is more common in larger breeds, but can occur in any dog of any size, regardless of whether they are purebred or a mixed breed.  

Breeds most commonly at risk include:

• Bernese Mountain Dog
• German Shepherd Dog
• Golden Retriever
• Labrador Retriever 
• Newfoundland
• Rottweiler

Breeders are able to screen their breeding stock for hip dysplasia before the dogs are bred from. Testing all potential breeding stock, where relevant, allows breeders to better understand the kind of genes a dog may pass on to its offspring, giving them the information required to avoid producing clinically affected puppies. The data from the BVA/KC Hip Dysplasia Scheme is also used to create estimated breeding values (EBVs). EBVs help owners to select lower-risk dogs for breeding. Making informed decisions from health test results enables breeders to adapt their breeding programmes and reduce the risk of the diseases appearing in future generations.

The BVA/KC hip dysplasia schemes operate to the highest standards of expertise, quality and consistency, which means breeders can have complete confidence in the rigour and accuracy of the scoring and grading processes.  The schemes also contribute to The Kennel Club’s unique database of hip scores, which in turn are used to create our estimated breeding values.

Key features of the schemes include:

• Highly qualified and experienced vets - The scheme currently has a panel of ten scrutineers who are all veterinary surgeons with advanced professional qualifications in veterinary radiology and/or orthopaedic surgery. They are extremely experienced in the assessment of hip and elbow radiographs, scoring and grading over 16,000 each year
• Two scrutineers – Radiographs submitted to the scheme are simultaneously assessed by two scrutineers working together as a team, whether side-by-side or remotely, and reaching a consensus on the score/grade
• Quality and consistency – We only accept high quality radiographs and these are reviewed using high-definition radiology-grade equipment and Visbion imaging software. The panel of scrutineers meet annually to discuss the findings of a quality control exercise and to review a sample of appeal radiographs. This ensures consistency and continuity of results over time.  Random selection of scrutineer pairs ensures that there is continuous peer review within the panel at each scoring/grading session
• New faster online submission - The new canine health scheme online submission portal means breeders can get their dog’s results returned to them within one week of payment. Breeders can also ask their vet to sign them up for automatic email updates on the status of their submissions, so they are kept informed on its progress.
• Appeals process – The BVA/KC scheme has a robust appeals process that is open to any breeder who disagrees with the score/grade for their dog. The radiographs are re-scored by a different pair of scrutineers who are unaware of the original score, and then reviewed by the chief scrutineer. The final appeal score is therefore based on the professional opinion of five scrutineers

How are the results used?

The total hip scores are published and can be compared with the median score for the breed (the score of the average dog in that breed, with equal numbers of dogs scoring higher and lower). Since dog breeds vary widely in the incidence of hip dysplasia, this allows individual dogs to be compared with others in the same breed, showing whether they are average, or better or worse, in their hip status.

Hip scores of both individual Kennel Club registered dogs and their relatives are published online via our health test results finder and are used to produce our estimated breeding values resource for the most commonly scored breeds. This links information about a dog's family (its pedigree information) with data from the BVA/KC health schemes. By linking this data together and looking at a dog's surrounding family it helps us estimate the types of genes a dog has and those that could be passed on to its puppies. This service is unique worldwide in dog breeding and is underpinned by the close working relationship between The Kennel Club and BVA.

When taking your dog for its x-ray, owners should remember that:

• Your dog must be at least 1 year old, but there is no upper age limit
• Your dog must be permanently and uniquely identified by way of a microchip or tattoo
• Your dog’s registration certificate from The Kennel Club and any related transfer certificates must be available so that the appropriate details can be printed on the radiographs
• microchip/tattoo numbers must also be printed on the radiographs
• You should sign the declaration (first part) of the certificate, to verify the details are correct and grant permission for the use of the results in data collection and research

Veterinary practices can submit radiographs for scoring under the BVA/KC Hip Dysplasia Scheme here: CHS online submission portal (bva.co.uk). Before making a submission, please visit the BVA’s website and read the Procedure Rules and Regulations explaining the requirements and procedure for radiography.

If you have any questions regarding the submission process, please contact them via email.

Yes, the scheme accepts online submissions from vet practices, and over half are now submitted online. There are plans to further increase the volume of online submissions and to gradually phase out paper-based submissions. The scheme is now able to score submissions with two scrutineers working as a pair remotely, and are currently running in-person scoring sessions in parallel with remote sessions.

Find out more about online submissions.

In many other schemes one scrutineer works alone and independently, with no central body providing oversight, and no ongoing quality control or validation. This means that scores or grades may lack consistency and reliability.  Some schemes accept lower quality images (e.g. JPEG files) whereas we only accept medical grade DICOM image files.

While scores or grades from other schemes can assess the degree of hip or elbow disease,  the results from other schemes are not directly comparable with the BVA/KC scheme and so this data cannot be used to inform estimated breeding values. 

For further information on the scheme, please visit the BVA website.

The names and results of dogs registered with The Kennel Club will be sent to us for recording on our database and will be made available:

• in the next available Breed Records Supplement
• on our Health Test Results Finder
• as an estimated breeding value, to aid owners in selecting lower-risk dogs for breeding, via our Health Test Results Finder

General advice

Ideally breeders should use dogs that that have an EBV which is lower than average (i.e. a minus number), and preferably with a confidence rating of at least 60%. Dogs with an EBV with a confidence less than 60% can still be used, but the higher the confidence, the more accurate the EBV will be. 

Lower doesn't have to be lowest

The lower the EBV, the better, but breeders do not need to search out the dogs with the lowest risk EBV. Selecting animals with a lower risk EBV than average will still lower the risk of hip dysplasia in the breed as a whole. 

EBVs help you make balanced breeding decisions

It is recommended that breeders make well balanced breeding decisions. At birth, each puppy will have an EBV that is the average of its parents. Therefore, dogs with an EBV which is higher than average can still be bred from, providing that it is mated to a dog with an EBV which is well below average (assuming that the confidence for both dogs is high). 

EBVs help maintain genetic diversity

Previously, the best advice was to ideally use dogs with a hip score of 0, which meant that many dogs could have been excluded from a breeding plan if their scores were a significant consideration. Excluding dogs from a breeding plan can have an impact on genetic diversity. By using EBVs, it is reasonable to use a dog with less than ideal individual BVA/KC scores, as long as the EBV indicates low genetic risk with good confidence. In such cases the hip condition of the offspring should be carefully monitored and preferably they should be hip scored themselves.

Hip dysplasia is a condition which is inherited in a complicated way not yet fully understood by scientists. Due to the complex nature of inheritance of this condition, it is still possible that affected offspring may arise from parents which have good EBVs. It is hoped that breeding appropriately from screened dogs will reduce the risk of producing affected offspring, and using EBVs reduces this risk even further, but it must be stressed that this is not a guarantee.

No. Hip dysplasia is a complex inherited disorder and is caused by a number of different genes and is also influenced by several environmental factors. DNA tests can be developed for conditions controlled by only one gene to definitively predict whether a dog will be clear, a carrier or affected, but not for conditions controlled by more than one gene.