Efficacy of a buccal meloxicam formulation for pain relief in Merino lambs undergoing knife castration and tail docking in a randomised field trial.

Objective To assess the efficacy of oral transmucosal meloxicam for pain relief in lambs at marking. Design A blinded, placebo-controlled, randomised, block design field study of 60 Merino lambs aged 7–10 weeks allocated to placebo and meloxicam treatments and studied in two cohorts of 30. Placebo-treated lambs received 1 mL/10 kg of drug vehicle and meloxicam-treated lambs received 1 mg/kg meloxicam at 10 mg/mL. Treatments were administered into the buccal cavity immediately before knife castration and hot-iron tail docking. Lambs were then released into a grassed paddock (0.34 ha). Time to mother-up was recorded and behaviours were observed every 15 min for 8 h and again for 45 min at 24 h. The sequence in which lambs exited the paddock with their mothers was then recorded. Weight change and wound scores were recorded 4 and 7 days after marking. Results Meloxicam did not affect mothering-up. In the 8 h following marking, meloxicam led to a 7-fold reduction (P < 0.001) in combined abnormal behaviours (hunched standing, standing with a stretched posture, walking stiffly). The meloxicam group spent significantly less time in standing postures and tended to spend more time grazing, suckling and in normal lying postures. At 24 h, the meloxicam group spent more time lying and less time standing. There was no effect of treatments on the sequence in which lambs moved into a fresh paddock or on weight change. Conclusions The buccal meloxicam formulation provided substantial analgesia to lambs on the day of marking. Slight benefits were evident the following morning.