ANALYSIS OF HIP-JOINT DYSPLASIA DEVELOPMENT IN DOGS

Hip joint dysplasia in dogs occurs mainly in large and heavy breeds. I t brings about changes on the acetabulum (socket) and the head of thig h bone, thus causing pain, tiredness, refusal to jump and refusal of i ncreased activity. Even though presently the genetic basis of developm ent of this disease, numerous literary sources indicate existence of p re-disposing factors that facilitate development in later stages of li fe. Diet and unbalanced development of skeleton and support tissues li gaments, joint capsule and musculature also have the effect on develop ment of dysplasia. We have analyzed acquired results of X-ray examinat ion of dogs - German shepherds. The size of the group was 4 206 and th e examination was aimed at incidence of hip-joint dysplasia during the period of 1977-1995 in the Slovak Republic. We have found out that in 1977 there were 70.7% positive cases out of the total number of exami ned individuals. Gradual exclusion of dogs with heavier grades of dysp lasia (D, E) decreased occurrence of dysplasia to current rate of 40.8 %. We considered it to be a high incidence rate. Internal structure of the positive group has changed. The number of dogs with the lightest grade of dysplasia (B) has increased, while the number of heavier grad e dysplasia (C, D, E) decreased. In other breeds of dogs, of which mor e than 20 have been examined at the clinic, the following results have been acquired: Slovak chuvash - 32%, Bavarian and Hannover bloodhound - 30.6%, Rotweiler - 28.6%, Newfoundland dog - 26.3%, Bern sheep-dog - 13.6%. At the same time we analyze the incidence of dysplasia in dog s whose parents were negative. Group of descendants of 11 negative mal es and 28 females consisted of 73 dogs. Through x-ray examination, 42. 5% of dogs were found to have dysplasia B, C and D at the age of 1 yea r.