Bupivacaine, Ketamine And Bupivacaine – Ketamine Epidural Anaesthesia In Bitches Undergoing Ovariohysterectomy

This research was conducted to analyze the analgesic effects of bupivacaine, ketamine and bupivacaine–ketamine combination on bitches undergoing ovariohysterectomy, and determine a suitable regional anaesthesia. Fifteen (15) apparently healthy bitches, aged 8-12 months and weighing 10 – 15kg were procured within and around Zaria, Kaduna State for this experiment. The animals were grouped into three (3), A, B and C, screened and allowed to acclimatize to the new environment. Premedication was instituted with 0.02 mg/kg atropine sulphate and 1mg/kg Xylazine. Group A was administered an epidural injection of 0.5 % bupivacaine hydrochloride at 1 mg/kg, Group B was administered an epidural injection of 50 mg/ml ketamine hydrochloride at 2 mg/kg and Group C was administered an epidural injection of bupivacaine and ketamine combination at 0.5mg/kg and 1 mg/kg respectively. Analgesic indices determined were time to sphincter relaxation, the onset of action, duration of analgesia and duration of muscle relaxation. A standard ovariohysterectomy procedure was carried out at the onset of analgesia on each experimental animal, lasting an average of 45 minutes. Bitches in the bupivacaine group took a longer time (73 ± 18.0 secs) to sphincter relaxation which was significantly different from the other groups. Ketamine took the shortest amount of time (15 ± 3.0 secs) which was almost immediate. The onset of analgesia was the shortest (3 ± 1.0 mins) in group B with ketamine only. The combination of ketamine and bupivacaine produced a longer duration (121 ± 7.0 mins) of analgesia and significant muscle relaxation (110 ± 20.0 mins). The combination of bupivacaine and ketamine produced superior analgesic effects than those of bupivacaine or ketamine alone used for epidural injection, and sufficient for painful surgeries such as ovariohysterectomy in dogs.