LAUSR

Abstract Only a few studies have examined the effect of neostigmine combined with lidocaine on epidural anesthesia in gelding horses. The purpose of this investigation was to evaluate clinical effects, ataxia, and the sensory block duration caused by adding neostigmine to epidural lidocaine in mares. Three independent treatments including neostigmine (NEOST), 2% lidocaine (LIDO), or 2% lidocaine combined with neostigmine (LIDO + NEOST) were administered to six mares using epidural catheters. Each animal received all treatments. A cutaneous pinprick nociception test with fine needle was used in perianal, sacral, and lumbar dermatomes in both antimeres. The response (attempt to kick, movement of the limbs, tail, or head toward the stimulus) was assessed immediately before and after each treatment (every 15 minutes in the first hour, and then every 30 minutes thereafter until the animal would go back to basal response). Analysis of variance ( P P > .05). No relevant changes in clinical and behavioral parameters were observed. In conclusion, adding neostigmine to lidocaine has not brought any relevant benefits to the epidural anesthesia in clinically normal mares.