Tail docking and castrating lambs: does the administration of local anaesthetic or meloxicam reduce the pain response exhibited?

Abstract

PICO question In healthy lambs, does the administration of local anaesthetic reduce the pain response after castration and tail docking compared to the administration of meloxicam? Clinical bottom line Category of research question Treatment The number and type of study designs reviewed Three prospective randomised clinical trials (RCT) and one clinical trial without stated randomisation were critically reviewed Strength of evidence Moderate to strong evidence in terms of their experimental design due to having three RTCs which are all relatively recent research. However, their implementation is moderate to weak as they fail to prove the hypothesis Outcomes reported In all four studies there was improvement in the pain related behaviours post administration of anaesthesia or analgesia. There is conflicting evidence on meloxicam’s efficacy, but this could be a result of time spent observing outcomes, which relates to the drugs onset of action and time of peak concentration. Lidocaine has consistently shown a reduction in acute abnormal behaviours irrespective of equipment used Conclusion Based on the studies appraised in this Knowledge Summary there is not enough evidence to determine whether local anaesthesia is more effective than meloxicam at reducing the pain exhibited by lambs undergoing castration or tail docking. It has been shown that the use of local anaesthesia in the form of injectable lidocaine will reduce acute pain displayed during marking but there remains conflicting evidence for meloxicam with likely benefits occurring after several hours 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.

Keywords

• lambs
• meloxicam
• local anaesthesia
• castration
• tail docking
• pain response