An Assessment of Tramadol-Xylazine-Ketamine-Diazepam Combination in the Horse

Abstract

Two sets of trials were carried out to evaluate the influence of tramadol premedication on xylazine-diazepam-ketamine anaesthesia in horses. Five horses comprising of both sexes (mean weight 276±39kg) were each anaesthetized twice. Treatment A (TXDK) consisted of intravenous injection of tramadol (2.5 mg kg ^-1), followed five minutes later by xylazine (1.1 mg kg ^-1), diazepam (0.11 mg kg ^-1) and ketamine (2.2 mg kg ^-1) while treatment B (SXDK) consisted of saline, xylazine, diazepam and ketamine of equal doses as treatment A. Post induction of anaesthesia, anaesthetic indices and physiological parameters were measured at 10 minutes interval for 60 minutes while blood were collected before and after each trial to evaluate haematological parameters.

The duration of lateral recumbency (DLR) was significantly (p<0.05) longer with TXDK (48.0±4.2 mins) when compared to that with SXDK (41.0±4.9 mins), while there were no significant difference in the duration of antinociception (DAN), number of attempts to stand (ATS), time to standing (TTS), and time to satisfactory limb co-ordination after standing (TSC). Similarly, there were no significant differences in the measured physiological and haematological parameters between and within the two groups. The quality of recovery from anaesthesia was adjudged good for both groups with no significant difference.

In conclusion, anaesthesia with xylazine-diazepam-ketamine following tramadol premedication at 2.5 mg kg ^-1 did not prolong the duration of antinociception but increased the duration of lateral recumbency. This showed that tramadol premedication prior to xylazine-diazepam-ketamine combination might not deepen analgesia produced by xylazine-diazepam-ketamine but might increase the duration of recumbency produced by the drug combination.

Key words: Anaesthesia, Analgesia , Horses, Ketamine, Premedication, Tramadol