All radiographs submitted to the BVA/KC Hip Dysplasia Scheme are assessed by means of scoring. The hip score is the sum of the points awarded for each of nine radiographic features of both hip joints. The lower the score the less the degree of hip dysplasia present. The minimum (best) score for each hip is zero and the maximum (worst) is 53, giving a range for the total of 0 to 106. The average score of the breed, or the 'breed mean score', is calculated from all the scores recorded for a given breed and is shown alongside its range thereby giving a representation of the overall hip status of the breed. All breeders wishing to try to control HD should breed only from animals with hip scores well below the breed mean score. Sires (fathers) to be bred from should only be ones whose progeny (offspring) have achieved consistently low scores. The same selection procedure should be used for bitches for breeding, since the use of animals with higher than ideal scores may make the risk of producing offspring with high scores much greater. This circumstance is not only disappointing and potentially costly in terms of compromised breeding plans, but may lead to subsequent civil court action. For the hip scoring scheme to be meaningful and successful in the attempt to control this serious disease it is important that all radiographs taken under the scheme are submitted for scoring, whatever the apparent state of the hips, in order that the information gathered is as relevant as possible. It is only by this means that proper conclusions may be drawn by the scheme's statisticians, geneticists and veterinary advisers. It is not hard to understand why things happen so quickly and how critical a whole series of factors in the dog's life are, when realising some animals treble their size and weight during a three- month period of adolescence. Getting all the many nutritional needs in the right quantity, to the right place and at the right time requires a mastery of logistics. However, it has to be realised that this apparent basic requirement overlays the parts played by  inheritance and other factors, for example the type of exercise taken and the degree of body weight.

Hip dysplasia, because it can be made up of a picture of joint looseness, new bone formation or bone loss and inflammation and pain, can show up in a range of signs from apparent soundness through lameness to degrees of

exercise intolerance. Combine these findings with the fact that some breeds and some individuals are more stoical than others and there is no predicting, just by looking from the outside, to what degree a particular dog has or hasn't got HD. More reliable is the clinical examination which is likely to reveal limitation of movement of  the affected hip, probably reduction in muscle mass of the limb and some degree of pain. Remember, a dog with HD in the normal course of life does not show discomfort by, say, yelping, mainly because the pain is likely to be continuous as opposed to sudden and unexpected. The only way to assess properly the presence or relative absence of HD is by radiography. This is an accurate photographic way of showing the position of the ball of the joint in relation to the socket and the presence and degree of any secondary changes.

An owner should make an appointment with their veterinary surgeon for hip radiography to be carried out under the scheme. This may require admission to the veterinary practice for a short period or a day. Sedation or general anaesthesia will be required since the manual restraint of animals during radiography is only permitted under exceptional circumstances. Additionally, the radiograph must be of the highest photographic quality and the projection of all the required structures must be as dictated by the rules of the scheme (copies of which are available from the BVA). The advice of the practice staff should be followed regarding any period of 'nil by mouth', the time of the appointment and the need in every case to present at the time of the procedure the Kennel Club registration and, if appropriate, transfer certificates. It is a requirement of the scheme that the registration number is indelibly printed on to the radiograph. It will be necessary for the owner of the dog or his agent to sign the scoring sheet there by signifying the identity of the animal in question and associated details, giving permission for the results to be published and to be subjected to genetical and statistical research. The minimum age of the dog at the time of the radiography is 12 months; there is no upper age limit. Dogs may not be scored under the scheme more than once. The cost of the procedure will be a composite of the veterinary surgeon's fee for taking the radiograph and the fee forwarded with the film to the BVA. The latter covers the fees paid to the scrutineers appointed under the scheme, a reimbursement of costs incurred by the Kennel Club and an administration charge made by the BVA.