A multicentre, prospective, randomised, blinded clinical trial to compare some perioperative effects of buprenorphine or butorphanol premedication before equine elective general anaesthesia and surgery.
Authors: Taylor P M, Hoare H R, de Vries A, Love E J, Coumbe K M, White K L, Murrell J C
Journal: Equine veterinary journal
Summary
# Editorial Summary Buprenorphine, a newly licensed μ-opioid agonist for equine use, had not been directly compared with the more established butorphanol (κ-agonist) in a large-scale clinical setting, despite their different pharmacological profiles suggesting potentially different analgesic effects. Researchers at six UK equine clinics conducted a prospective, randomised, blinded trial in 89 horses undergoing routine elective surgery; all animals received standard premedication (acepromazine, NSAID, romifidine) followed by either buprenorphine or butorphanol intravenously before induction with diazepam/ketamine and maintenance with isoflurane. Between 3 and 6 hours post-operatively, horses receiving buprenorphine demonstrated significantly lower pain scores on a simple descriptive scale compared to those given butorphanol, whilst physiological variables, recovery quality, and standing times remained equivalent between groups. These findings suggest that buprenorphine offers superior post-operative analgesia without compromising safety or recovery characteristics, making it a worthwhile consideration for premedication protocols in elective equine surgery—though the clinical significance of pain score differences should be weighed against current practice, availability, and cost considerations within individual practices.
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Practical Takeaways
- •Consider buprenorphine over butorphanol for equine premedication if superior post-operative analgesia is a priority, particularly for the 3-6 hour post-operative window
- •Both agents are safe to use in clinical practice with standard equine anaesthetic protocols and produce equivalent effects on vital signs and recovery quality
- •Buprenorphine's improved analgesic profile may reduce post-operative pain management requirements, potentially benefiting horse welfare and recovery
Key Findings
- •Buprenorphine premedication resulted in significantly lower post-operative pain scores (3-6 hours post-op) compared to butorphanol
- •No significant differences between buprenorphine and butorphanol groups in physiological variables during anaesthesia or vital function post-operatively
- •All 89 horses recovered successfully with no mortality or serious morbidity, with most standing within 1 hour of anaesthesia cessation
- •Both opioids were compatible with conventional equine anaesthetic protocols using acepromazine, romifidine, diazepam/ketamine, and isoflurane