It was around 35 years ago that the British Veterinary Association (BVA) and the Kennel Club developed a scheme to assess the degree of hip malformation of dogs through radiography. There are currently 100 breeds surveyed by the scheme in the U.K. The first scheme awarded a status of either Pass or Fail, this was them followed by a scheme, of PASS, FAIL, or BREEDERS LETTER, and in 1984 the scheme as we know it today was introduced, which is an assessment on nine criteria, and scores of between 0 and 6 are allocated for all the criteria with the exception of the caudal acetabular edge which has a maximum score of 5.

The best score that can be acheived is 0 - 0 which means,after each radiograph for each hip has been evaluated there is no abnormality. The worst score then is 53-53. The two scores are added together to give a total hip score. The British system of scoring x-rays for hip dysplasia has an advantage over scoring schemes used in other countries because we assess a number of specific anatomical landmarks which ensures a relatively objective evaluation for each joint. The hip joint is a complex one, it is this joint that transfers power from the hind leg muscles to the body, with the supporting structures of ligaments and tendons, the hip becomes a unit. The surfaces of cartilage are lubricated by joint fluid which ensures a pain free action.

Under the Kennel Club / B.V.A. scheme a dog may be x-rayed and scored. The dog must be over one year old to be hip scored, although it can be of any age to be x-rayed, and there is no upper age limit. The dogs Kennel Club registration number must be recorded on the x-ray and the Left and Right side must also be marked. It is important that the radiographs are clear and of good quality, with good contrast , and with no under or over exposure. For this reason dogs are x-rayed under anesthetic, it is helpful to relax the dog, and achieve better positioning. It is unrealistic to expect that excellent radiograph technique will always be consistent, so it is therefore somtimes necessary to make compromises when allocating scores. When it comes to image interpretation it is recognised that even experienced observers can make mistakes in the evaluation of abnormalities, to minimise this error there are two scrutineers to examine each radiograph.

Chris Clucas