In recent years, radiologic detection of passive joint laxity, i.e., distraction radiography, has become important in the early diagnosis of hip dysplasia in dogs. In this study, Ortolani Diagnosis and Distraction Index (DI), i.e., radiographic passive joint laxity, were determined for 122 dogs between 3- and 9-months-of-age, and this data was compared with adult period control radiographies (the period after 18-months-of-age). By this means an attempt was made to determine the relation between DI and Ortolani diagnosis, Norberg angle and Federation Cynologique Internationale (FCI) classification. A high correlation was established between the results taken by two types (PennHip and wooden lath) of distractors. Although no correlation was found between breed, age, sex, body weight and DI measurement, a significant correlation was found between DI measurement and FCI classification and Norberg angles after the age of 18 months. On the other hand, no significant correlation was found between Ortolani diagnosis and DI measurement and FCI-Norberg data after the age of 18 months. Consequently, the usage of distraction radiography was observed to be more effective than other clinical and radiographic methods in the early diagnosis of hip dysplasia in dogs.