Ultrasonographic anatomy of the palmar region of the carpus of the dog.

The palmar region of the canine carpus may be injured by traumatic, inflammatory, infectious, neoplastic, and degenerative disorders. The normal ultrasonographic anatomic features of the dorsal region of the canine carpus have been published, however information regarding the palmar region is currently lacking. The aims of this prospective, descriptive, anatomic study were (1) to describe the normal ultrasonographic characteristics of the palmar carpal structures in medium to large-breed dogs, and (2) to establish a standardized ultrasonographic protocol for evaluating them. As in the previously published study, the current study consisted of two phases: (1) identification phase, in which the palmar structures of the carpus were identified ultrasonographically in fifty-four cadaveric specimens and an ultrasonographic protocol to examine them was developed; and (2) descriptive phase, in which the ultrasonographic characteristics of the main palmar structures in twenty-five carpi of thirteen living healthy adult dogs were documented. The tendons of the flexor muscles of the carpus and digits, the superficial and deep parts of the retinaculum flexorum, the carpal canal and the median and ulnar neurovascular structures were ultrasonographically identified and described. Findings from the current study can serve as a reference for evaluating dogs with suspected injury involving the palmar carpal region using ultrasonography.