Evaluation of bupivacaine, xylazine and bupivacainexylazine combination for induction of epidural analgesia in dogs

Eighteen dogs presented for castration, spaying, tail amputation and herniorraphy at Bombay Veterinary College were randomly divided into 3 groups of 6 each. In all groups, epidural analgesia was induced by injecting 0.5% bupivacaine 2 mg/kg in group-I, xylazine 1 mg/kg in group-II and combination of bupivacaine 1 mg/kg and xylazine 0.5 mg/kg in group-III. Onset of analgesia was recorded within 2.83±0.30 min, 4.66±0.33 min and 3.33±0.2 min following epidural injection in groups-I, II and III, respectively. A significantly rapid induction of analgesia was recorded in group-I than group-II and III and in group-III than group-II. Duration of analgesia was 110.66±5.58 min, 92.83±3.72min and 128.83±4.42 min in groups-I, II and III, respectively. The duration of analgesia was significantly longer in group-III than groups-I and II. Further the degree of muscle relaxation was better in group-Ill than in groups-I and II. The area of analgesia was up to l rib in group-III, while it was only up to 13^th rib in groups I and II. Recovery from analgesia was recorded within 134.50±7.18, 120.16±9.73 and 153.33±4.43 min in groups-I, II and III, respectively. None of the animals in showed any excitement during recovery from analgesia.