Comparative anatomy analysis of the accessory carpal bone across dog and cat breeds

This study investigates the morphological variation of the accessory carpal bone in mixed-breed cats and dogs of different breeds, focusing on 3D shape differences across species. Geometric morphometric analysis was applied to 3D models of 10 dogs and 15 cats, aiming to explore species-specific adaptations in carpal bone morphology. Cats (mix breeds) exhibited negative values for PC1, indicating more compact and slender carpal bones, consistent with their enhanced mobility and smaller body sizes. Both small and large dog breeds displayed positive PC1 values, indicating that the observed shape variation does not directly reflect body size but rather species- or breed-specific morphology. These findings were supported by centroid size analysis, which correlated with the shape variation along PC1. The lack of significant correlations between accessory carpal bone shape and Procrustes distance suggests that, while this may influence skeletal morphology, genetic factors likely play a more substantial role in shaping the carpal bone. This study highlights the utility of geometric morphometry in detecting species-specific skeletal adaptations and emphasizes the potential of this method to explore functional morphology in domestic carnivores. In conclusion, understanding the morphological variation of the accessory carpal bone in dogs and cats mixed breeds contributes to veterinary anatomy and has practical applications in veterinary medicine, particularly in surgical and rehabilitation practices. Therefore, the results contribute to a deeper understanding of carpal bone variation in cats and dogs, with implications for functional and evolutionary studies.