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PICO question

In horses undergoing lameness investigation, does sedation with a2-adrenergic agonists alone versus sedation with a2-adrenergic agonists in combination with butorphanol tartrate effect the degree of lameness?


Clinical bottom line

Category of research question


The number and type of study designs reviewed

Six papers were critically reviewed. There were two crossover clinical studies, three crossover controlled clinical studies and a randomised controlled clinical study

Strength of evidence


Outcomes reported

There was limited evidence to suggest that xylazine and romifidine in combination with butorphanol has an effect on forelimb lameness and that detomidine has an effect on hindlimb lameness.

Most evidence suggests that xylazine alone or in combination with butorphanol has no effect on the lameness


In general, sedating a horse with an a2-adrenergic agonist alone or in combination with butorphanol tartrate does not change the baseline degree of lameness. Due to the large variation in the measurements, the small magnitude of few significant effects and the inconsistency of these significant findings, there is insufficient evidence to recommend avoiding the use of sedation in cases where it would increase the safety of those involved. However, regardless of protocol used, clinicians must appreciate the possibility of individual horse variation


How to apply this evidence in practice

The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources.

Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.


Open Access Peer Reviewed