Caudal Extradural Analgesia with Lidocaine, Xylazine, and a Combination of Lidocaine and Xylazine in the Iranian River Buffalo (Bubalus bubalis)

To compare the time of onset, duration of action and the extent of analgesiaproduced by a lidocaine/xylazine combination with that produced by lidocaine and xylazinealone after injection into the caudal extradural space of the iranian river buffalo.design- observer-blind prospective descriptive trial, latin square design.animals- eleven adult (aged over 2 years) female non-gravid healthy iranian riverbuffaloes (bubalus bubalis), weighing from 450 to 650 kg.procedure- caudal extradural analgesia was achieved in buffaloes on 3 occasions at 14-dayintervals by injection of 2% lidocaine (l; 0.22 mg kg-1), 2% xylazine (x; 0.05 mg kg-1), anda combination of 2% lidocaine(0.22 mg kg-1) / 2% xylazine (lx; 0.05 mg kg-1) in a latinsquare design. analgesia was determined by the lack of response to pin-prick andhaemostat pressure in the skin of the caudal areas.results- onset of analgesia for x was significantly longer (5.5 ± 0.7 minutes) than that forl or lx. duration of analgesia was significantly longer for lx (172.3 ± 17.7 minutes) thanfor either drug used alone (lidocaine, 79.5 ± 5.7 minutes; xylazine, 136.4±11.4 minutes). inx and lx groups, the level of analgesia ascended to thoracic segments; however, inlidocaine-treated buffaloes thighs, flank, and udders remained sensitive. in all buffaloes,xylazine, administered either alone or with lidocaine, induced mild to moderate ataxia.conclusions – the lx combination provided a more rapid onset, a longer duration ofanalgesia, and a more cranial spread of analgesic effect compared with either drug alone.clinical relevance: the lx combination may offer a fast and long lastinganesthesia/analgesia to perform obstetrical and surgical procedures without the need for reinjection.