Radiographic evaluation of the forelimb bone development in maned wolves (Chrysocyon brachyurus)

This study aimed to assess the fusion of growth plates and the development of secondary ossification centres in the forelimb bones of maned wolves (Chrysocyon brachyurus), contrasting the findings with established data from domestic dogs. Three maned wolves, comprising one male and two females, initially aged between 3 and 4 months, were subjected to monthly radiographic evaluations until 10–11 months of age, followed by bimonthly assessments until 18–19 months of age, encompassing both forelimbs. The closure times of growth plates were observed as follows: supraglenoid tubercle (7–8 months), proximal humerus (17–19 months), distal humerus (8–9 months), medial epicondyle of the humerus (8–9 months), proximal ulna (9–10 months), proximal radius (13–15 months), distal ulna (13–15 months) and distal radius (17–19 months). Statistical analysis revealed significant differences in the areas of secondary ossification centres in the proximal epiphyses of the humerus and radius, respectively, observed from the initial evaluation at 8–9 months and 6–7 months. Conversely, the epiphyses of the supraglenoid tubercle, distal humerus, proximal ulna, distal ulna, medial epicondyle of the humerus and distal radius did not exhibit significant area differences between 3–4 months and 4–5 months, yet notable distinctions emerged at 5–6 months. In summary, while the radiographic appearance of epiphyseal growth plates and secondary ossification centres in maned wolves resembles that of domestic dogs, closure times vary. These findings contribute to understanding the dynamics of epiphyseal growth plates in this species.