Developmental Myopathy in the Canine

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. 1-4 Dogs 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. 3 Hence, 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. 5 In the development of this technique, it was observed that as early as 4 weeks of age, in