How many carpal bones are typically present in the canine carpus?

• A. Eight
• B. Six
• C. Nine
• D. Seven

Answer: (A)

In dogs, the carpus is composed of a specific set of small bones arranged in two rows, with an additional accessory bone on the palmar side. The proximal row has three bones: radial, intermediate, and ulnar. The distal row has four bones, labeled I through IV. In addition, the accessory carpal bone sits at the ulnar/palmar aspect and is counted as part of the carpal set. When you add them up—three proximal bones, four distal bones, plus the accessory bone—you get eight carpal bones in the canine carpus. That’s why eight is the typical number. The other counts would miss one of these components (either omitting the accessory bone or miscounting the rows), so they don’t match the standard canine carpal anatomy.