HIP DYSPLASIA HAS A GENETIC TRAIT THAT IS AFFECTED BY ENVIROMENTAL FACTORS
Hip dysplasia is the abnormal formation of the hip socket that, in its more severe form, causes crippling lameness and painful arthritis of the joints. It is a condition that begins in dogs as they grow  resulting in instability and laxity of the hip joint causing progressive joint changes. Continual abnormal movement of the femoral head deforms the socket. The long-term response to this joint laxity is the progressive loss of cartilage, the development of scar tissue around the joint, and the formation of bone spurs around the ball and socket. Rapid weight gain and growth through excessive nutritional intake and inappropriate exercise can complicate the development of HD. Worst case senario is that some young dogs are put to sleep or have shortened lives in pain.

One factor in the prevention of this condition is breeding from suitable parents, X-raying hips and their evaluation provides invaluable information when choosing brood bitches and stud dogs. There is no magic formula or number (hip score) to guide us, and there are many other factors to be taken into consideration. However, breeders cannot make an informed decision without all of the information that could be available. Hip 'dysplasia' is a polygenic disease, current estimates state that more than one hundred genes code for it. It is important to recognise that environmental factors can have a great influence on the degree of dysplasia, and can influence whether an animal with the genes that code for it will develop the clinical problem. The Hip Dysplasia Scheme was established by the BVA and Kennel Club in 1965 to reduce the incidence and severity of the condition. Radiographs are scored by BVA appointed Scrutineers and the hip score, from 0 to 106, is made up of the total number of points given for different features in the hip joint. The lower the score the better. "Interpretation and use of BVA/KC hip scores in dogs" by Ruth Dennis gives detailed information and is available on the internet.

Also the "Pupscan Project" was established in early 2015 to research and identify the factors leading to abnormal joint development in dogs. This project aims to separate predominantly genetic causes from the many acquired conditions that can damage joints. Using the most modern diagnostic Ultrasound technology and a precise measurement analysis of the whole hip, a non-invasive imaging technique has been developed to evaluate puppies in the early months of life in order to establish the presence, or absence, of normal healthy joint development. Whilst this is very new and may not be available in all locations, it is a very interesting development.

The ISCGB Health Committee is of the opinion that if a dog is x-rayed under one of the health schemes, all x-rays should be submitted to the BVA, regardless of their expected score, for several reasons. By omitting scores that are likely to be higher, the breed average is artificially reduced, meaning the published average is not accurate and is understated.  To give us a true picture of the breed average, it is important that these higher scoring dogs plates are submitted so they can be included in the calculation. Continued with-holding of x-rays for dogs believed to be higher scoring, will cause the breed average to reduce still further over time and those people who choose not to use dogs with a score above the breed average are disadvantaged, and the gene pool is further reduced. The ISCGB publish all UK hip scores on the ISCGB website and in the health database.  These are of huge benefit to others who may be researching lines to see the familial history of health test results. The scores of siblings and ancestors are often taken into account when planning a mating.  If an x-ray is not submitted for scoring, it cannot contribute to that knowledge and assist in someone's future plans.

Breeders are already disadvantaged by only having a small percentage of each litter evaluated, reducing the information available. Our Code of Ethics states that health tests should be undertaken, it does not state that a higher scoring dog shouldn’t be bred from. If a breeder feels that a dog’s breed attributes outweigh a higher hip score, they can still decide to breed. Their decision is then made on a more informed basis for both the breeder, stud dog owner and prospective puppy purchasers as there is an actual score to base this decision on.  Otherwise it’s a guessing game.

Every breeder wishes to produce an entire litter of fit, healthy and long lived puppies that go into loving forever homes, this may be unrealistic, but we can try.

Of course the new owner must continue good management to avoid this condition. Puppies need appropriate exercise, 5 mins per month of life ie 15 mins for a 3 month old puppy, each day, no climbing stairs or jumping in and out of cars. Swimming is excellent as this builds muscle without impact on joints. Also a good diet without allowing the puppy to become obese promotes steady growth.

If you would like more information the BVA produce an excellent leaflet about the condition. Click here to visit their page.