What is Hip Dysplasia and how is it caused?
The hip consists of a cup-shaped socket in the pelvis in which the roughly-spherical head of the thigh bone sits. The bones are held in place by the soft tissues of the joint capsule, the ligaments and, to some extent, the surrounding muscles. The term 'hip dysplasia' is used to describe hip joints which are loose, ill-fitting, or both. In the foetus and the young puppy, the skeleton is made up of a soft, cartilaginous framework which gradually ossifies and becomes harder as the animal grows. Any looseness or problems with the fit of the hip joint will result in abnormal stresses being exerted on the softer components of the skeleton which will then ossify in an abnormal conformation. Even after the skeleton becomes mature at about one to two years of age, abnormal stresses on the bones and soft tissues of joints showing dysplasia will continue to cause bony remodelling and the production of arthritic bone.
Hip dysplasia is a disease which is governed partly by genetic features and partly by environmental factors such as nutrition, bodyweight, neutering and exercise. According to the British Small Animal Veterinary Association, hip dysplasia progresses significantly between 6 and 18 months of age, with most changes developing before 2 years old. However, most dogs with hip dysplasia show no clinical signs of the condition until later in life, if at all. Unless dogs are tested before being used for breeding, the genes for hip dysplasia may be passed on to their offspring.
Is Hip Dysplasia a problem in Beardies?
Fortunately, hip dysplasia is not a serious problem in Bearded Collies, and it is unlikely to become one as long as breeders take into account hip scores when planning a litter. The latest Kennel Club statistics show a 5-year rolling mean (for Beardies scored between 1 Jan 2017 and 31 Dec 2021) of 9.5, the same as the 15-year breed mean of 9.5. The breed median was 9.
How can Hip Dysplasia be diagnosed?
An assessment scheme run jointly by the Kennel Club and the British Veterinary Association (BVA) is used to diagnose hip dysplasia. The scheme uses radiographs (X-rays) of the dog's hips, taken when the dog is lying on its back with its hind legs extended and turned inwards so that the thigh bones are parallel. The advantage of this position is that it can be reproduced consistently on different occasions. Sedation or general anaesthesia is necessary to allow accurate positioning without the need for the animal to be held. The radiographs must be identified accurately with the dog's Kennel Club registration, microchip or tattoo number, the date and a right/left marker.
What is the Kennel Club Hip Dysplasia Scoring Scheme?
The hip radiographs are submitted to the BVA and examined by two veterinary surgeons from a panel of expert scrutineers. For each hip joint, nine anatomical parameters are examined and allocated a score ranging from 0 (perfect) to 6 (worst). The 0 - 6 scoring applies to eight of the nine parameters; the ninth (the caudal acetabular edge) has a maximum score of 5. This gives a scoring range of 0 - 53 for each hip (0 - 106 total score). The lower the score the less the degree of hip dysplasia.
What do I need to know if I am buying a puppy?
The Bearded Collie Club strongly recommends anyone buying a puppy to check that both the sire and the dam have been hip scored, as the recent breed health survey showed a few cases where hip scoring had not been done. You can use the Kennel Club's Health Test Results Finder to find the hip score of any dog tested under the BVA/KC scheme. However, the scores for foreign dogs imported to the UK are not recorded because the scoring schemes in other countries are different. The BVA recommends that imported dogs have their hip x-rays submitted for scoring under the BVA/KC scheme, but if this has not been done there is a document you can download from the Hip scheme page on the BVA web site which roughly compares the various schemes. Hip scoring is a mandatory requirement for the KC Assured Breeder Scheme.
The BVA advice is that only dogs with scores below the median should be used for breeding.
Can breeders take environmental factors into account?
The radiograph records the physical end-result of a combination of genetic and environmental factors and it remains the only tool we have for identifying dogs with hip dysplasia. However, because Bearded Collie breeders were among the first to achieve widespread adoption of the test for hip dysplasia and continue to use it, they have recently been able to take advantage of an additional resource, the Kennel Club's Estimated Breeding Values (EBVs) tool. EBVs estimate the genetic potential (risk) that a dog will pass the genes for hip dysplasia to its progeny, stripping out environmental factors. Using EBVs to support mating decisions should lead to faster progress in reducing the prevalence of disease.
For more information on EBVs and how they can be used by breeders see our EBVs page, or the Kennel Club website page More Information About EBVs.
Last updated: 09 August 2022