Session 28, Performance and Health in Young Horses, HM5.8 BREED VARIATIONS IN THE DISTRIBUTION OF OSTEOARTICULAR LESIONS IN HORSES AT WEANING

Juvenile Developmental Orthopaedic Diseases (DOD) affect most horse breeds and their occurrence is reported to be increasing. In order to establish the prevalence of DOD in French breed horses, 134 Thoroughbreds (Tb), 161 French Trotters (FT) and 98 Selle Français (SF) foals kept on 21 stud farms were examined radiographically at weaning. Radiographic files (including views from the front and hind interphalangeal and fetlock joints, carpi, hocks and stifle joints) were analysed by 3 veterinarians. For each joint, osteoarticular lesions were graded according to a standardised protocol depending on their severity. The scores of all the images on the 10 radiographs were added to calculate a global radiographic score. Differences in the distribution of the lesions were evaluated using an analysis of variance. SF were globally more severely affected than FT and Tb (p<0.001). Considering the regional distribution of the lesions, SF were more severely affected on the front fetlock (p<0.001), on the dorsal aspect of the hind fetlock (p<0.001) and on the femorotibial joint (p<0.05). FT were more severely affected on the plantar aspect of the hind fetlock (p<0.001) and the tibiotarsal joint (p<0.01). The present study shows that osteo-articular lesions differ between breeds independently of their use and training regimens.