High two-point nerve block, horse

Sites for the high two-point nerve block in a horse. The lateral palmar nerve (LPN) can be blocked using a 25-gauge, 1.6-cm (5/8-inch) needle as it courses subcutaneously along the medial surface of the accessory carpal bone. This location is proximal to where the palmar metacarpal nerves branch from the lateral palmar nerve. The medial palmar nerve (MPN) is blocked by using a 25-gauge, 1.6-cm needle to inject anesthetic subcutaneously along the medial edge of the flexor tendons. Amelioration or resolution of lameness after the high two-point nerve block localizes lameness to the proximal aspect of the metacarpus or distal aspect of the carpus when a low four-point nerve block has failed to ameliorate lameness.