HIP DYSPLASIA in dogs is a hereditary disease, common to many large breeds; a notable example is the German shepherd breed in which as many as 50% of the dogs are affected.1-4Dogs which will develop the disease cannot have the condition diagnosed at birth. In most instances, radiographic diagnosis is not possible until after 8 weeks of age and in mild cases not until 6 to 12 months.3,4 Though the etiology of hip dysplasia in the dog is unknown, the wide variety of acetabular and femoral changes observed appear to be the consequence of joint laxity.3Hence, studies of factors affecting joint laxity offer promise of determining the etiology of the disease. Recently, a technique was developed to adjudge laxity of the hip joint in puppies.5In the development of this technique, it was observed that as early as 4 weeks of age, in