A seven year old Percheron cross gelding was presented to the clinic for an evaluation of a lameness affecting the left hind limb. The horse jogged 2/5 lame on the left hind, and showed a strongly positive hock flexion test. Injection of the tarsometatarsal joint with lidocaine hydrochloride eliminated the lameness. Radiographs revealed the presence of advance degenerative joint disease of the tarsometatarsal and distal intertarsal joints.