Early diagnosis of canine hip dysplasia

The aim of the present study was to enumerate prognostic parameters for development of canine hip dysplasia (CHD) in growing dogs, how these parameters might correlate with the pathogenesis of hip dysplasia, and if these parameters could be used to predict development of disease. By monitoring subjects evaluated at an early stage and managed in a conservative manner, various parameters obtained at early monitoring were correlated with the development of CHD until skeletal development was achieved. The study included 92 puppies with an age between 12 and 28 weeks assessed for hip dysplasia and then reevaluated after complete development of the skeletal system between 12 and 20 months of age. Puppies were divided into two groups according to age, based on structural differences related to diverse grades of ossification. The first group was composed of puppies between 12 and 16 weeks, while the second group comprised puppies between 17 and 28 weeks. Early diagnosis was carried out by orthopaedic examination with the subject anaesthetised. During palpation of the joint, an Ortolani test was performed and the angles of reduction (AR) and subluxation (AS) were measured. Radiographic examination included standard ventro-dorsal view, projection in distraction using the method of Badertsher, with a modified distractor and measurement of the distraction index (DI) and dorsal acetabular rim (DAR) views. Puppies were evaluated after one year of age by ventro-dorsal views and classified according to FCI grading. A total of 17 dogs had grade A (normal), 15 grade B (transition), 34 grade C (slight dysplasia), 17 grade D (moderate dysplasia), and 9 animals had grade E (severe dysplasia). Significant correlation was found between the data obtained during early evaluation and the different FCI grades. A CHD Global Index Score, calculated by the values of AR, AS, DI and DAR, was used to evaluate the probability that puppies would develop different grades of dysplasia. The Ortolani test and the values of AR, AS, DI, and DAR if assessed individually, can predict the development of dysplasia. However, when grouped together in the Global Index Score these parameters have more significant and reproducible prognostic value. The resulting probability curves furnish reliable information about the evolution of CHD in puppies with a developing skeletal system and reliably predict if a joint will develop dysplasia that compromises or lowers the quality of life to a degree that would warrant preventive treatment.