Canine hip dysplasia is a very common degenerative joint disease seen in dogs.
Hip dysplasia results from the abnormal development of the hip joint in a young dog. It may or may not be bitateral, affecting both right and left sides. It is brought about by the laxity of the muscles, connective tissue and ligaments that should support the joint. Most dysplastic dogs are born with normal hips but due to genetic and possibly other factors, the soft tissues that surround the joint start to develop abnormally as the puppy grows. The most important part of these changes is that the bones are not held in place but actually move apart. The joint capsule and the ligament between the two bones stretch, adding further instability to the joint. As this happens, the articular surfaces of the two bones lose contact with each other. This separation of the two bones within a joint is called subluxation and this, and this alone, causes all of the resulting problems with the disease.
Dogs of all ages are subject to the symptoms of hip dysplasia and the resultant osteoarthritis. In several cases, puppies as young as 5 months will begin to show pain and discomfort during and after vigorous exercise. The condition will worsen until even normal daily activities are painful. Without intervention, these dogs may be unable to walk at all by a couple of years of age. In most cases however, the symptoms do not begin to show until middle or later years.
The current BVA/KC scoring scheme has been in operation since 1984. Dysplasia means abnormal development and the degree of hip dysplasia present is indicated by a score assigned to each hip. The hip score is the sum of the points awarded for each of nine aspects of the x-rays of both hip joints. The minimum hip score is 0 and the maximum is 106 (53 for each hip). The lower the score, the less the degree of hip dysplasia present. An average (or mean) score is calculated for all breeds scored under the scheme. At the 1st of November 2011, the breed mean score for the Old English Sheepdog was 18. The median for the breed was 12. The BVA recommend breeding from animals with hip scores well below the breed mean score and ideally below the median score for the breed.
The minimum age for hip scoring is one year and each dog is only ever scored once under the scheme.
Owners should make an appointment with their vet who can take the required x-ray. The vet then sends the x-ray to the British Veterinary Association where it is examined and "scored" by a panel of experts. Once the x-ray has been scored, the result is returned to the vet who relays it to the owner. A copy is sent to the Kennel Club for recording on the registration database and published in the Breeds Record Supplement.
There is a time limit of 45 days and a set procedure for appealing against results under the Scheme.
Further information is available from the British Veterinary Association - http://www.bva.co.uk/