Can sedation be used for equine lameness investigation?



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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


Bassage, L.H. & Ross, M.W. (2010). Diagnostic Analgesia. In: Diagnosis and Management of Lameness in the Horse: Second Edition. 2nd ed. Saint Louis: W.B. Saunders, 100–135. DOI:

Beck Júnior, A.A., De La Côrte, F. D., Brass, K.E., Dau, S.L., Silva, G.B. & Camillo, A.. (2019). Effect of Xylazine and Butorphanol on Experimental Hind Limb Lameness in Horses. Journal of Equine Veterinary Science. 73, 56–62. DOI:

Buchner, H.H., Kübber, P., Zohmann, E. & Peham, C.H. (1999). Sedation and antisedation as tools in equine lameness examination. Equine Veterinary Journal. 30(S30), 227–230. DOI:

De Cozar, M.J. (2019). Can I give alpha-2 agonists for blocking and accurately assess the horse’s lameness once blocked? Equine Veterinary Education. 31(2), 111–112. DOI:

Moorman, V.J., Bass, L. & King, M.R. (2019). Evaluation of the effects of commonly used α2-adrenergic receptor agonists alone and in combination with butorphanol tartrate on objective measurements of lameness in horses. American Journal of Veterinary Research. 80(9), 868–877. DOI:

Morgan, J.M., Ross, M.W., Levine, D.G., Stefanovski, D., You, Y., Robinson, M.A. & Davidson, E.J. (2020). Effects of acepromazine and xylazine on subjective and objective assessments of forelimb lameness. Equine Veterinary Journal. 52(4), 593–600. DOI:

Pilsworth, R. & Dyson, S. (2015). Where does it hurt? Problems with interpretation of regional and intra-synovial diagnostic analgesia. Equine Veterinary Education, 27(11), 595–603. DOI:

Rettig, M.J., Leelamankong, P., Pungsri, P. & Lischer, C.J. (2015). Effect of sedation on fore- and hindlimb lameness evaluation using body-mounted inertial sensors. Equine Veterinary Journal. 48(5), 603–607. DOI:

Ross, M.W. (2010). Movement. In: Diagnosis and Management of Lameness in the Horse: Second Edition, 2nd ed. Saint Louis: W.B. Saunders, 64–80. DOI:

Seitzinger, A.H., Traub-Dargatz, J.L., Kane, A.J., Kopral, C.A., Morley, P.S., Garber, L.P., Losinger, W.C. & Hill, G.W. (2000). A comparison of the economic costs of equine lameness, colic and equine protozoal myelocencephalitis (EPM). Proceedings of the 9th International Symposium on Veterinary Epidemiology and Economics.

Da Silva Azevedo, M., De La Côrte, F.D., Brass, K.E., Gallio, M., Pozzobon, R., Lopes, M.A.F. & Lopes, L.F.D. (2015). The Use of Xylazine or Acepromazine Does Not Interfere in the Lameness Evaluation by Inertial Sensors. Journal of Equine Veterinary Science. 35(1), 27–30. DOI:





Vol. 6 No. 2 (2021): The second issue of 2021

Section: Knowledge Summaries

Categories :  Small Animal  /  Dogs  /  Cats  /  Rabbits  /  Production Animal  /  Cattle  /  Sheep  /  Pig  /  Equine  /  Exotics  /