A comparison of the effects of two volumes of local analgesic solution in the distal interphalangeal joint of horses with lameness caused by solar toe or solar heel pain

The response of horses, with solar pain in the dorsal or palmar aspect of t he foot, to 6 or 10 mi local analgesic solution administered into the dista l interphalangeal (DIP) joint was examined. Lameness was induced in 7 horse s by creating solar pain in the dorsal aspect of one forefoot and, at anoth er time, the palmar aspect of the other forefoot with set-screws inserted i nto a custom-made shoe. Horses were videotaped trotting before and after ap plication of set-screws and, in separate trials, after 6 or 10 mi local ana lgesic solution was administered into the DIP joint. Lameness scores were a ssigned by examining videotaped gaits. Scores were significantly lower (P l ess than or equal to 0.05) for horses with set-screws applied to the angles of the sole and receiving 10 ml, but not 6 mi, local analgesic solution in to the DIP joint. Scores were significantly lower (P < 0.05) for all horses with set-screws in the dorsal margin of the sole receiving either volume o f local analgesic solution. Analgesia of the DIP joint was less effective i n desensitising the angles of the sole than in desensitising the dorsal mar gin of the sole, and 10 mi local analgesic solution was more effective than 6 mi in desensitising these regions. The response of horses with solar pai n to local analgesic solution in the DIP joint was influenced by the volume administered and the region of sole affected.