The effect of a non-steroidal anti-inflammatory drug on the distance travelled by reindeer (Rangifer tarandus tarandus) in the wilderness after clamp castration — a pilot study

Abstract

Background During seasonal round-ups, free-grazing reindeer are gathered from natural pastures. Reindeer bulls removed from breeding are clamp castrated, traditionally without analgesia, and then released back into the wild. The new Finnish Animal Welfare Act requires the use of analgesia in painful procedures. A single dose of the non-steroidal anti-inflammatory drug meloxicam may maintain therapeutic plasma concentrations for 2–3 days in reindeer. No studies have been conducted on the effect of meloxicam on the behaviour of castrated reindeer in the wild after the procedure. We installed GPS collars on 16 male reindeer (5y, 130–160 kg), chosen to be castrated as a standard procedure during the round-up. Of these, eight were randomly selected to receive approximately 0.5 mg/kg of meloxicam subcutaneously (NSAID) and eight received no analgesia (TRAD). From the GPS data, we calculated the daily distances travelled by the reindeer during the three days after castration and analysed the differences between the treatments using a GEE model. Fixed factors were treatment (NSAID or TRAD), days (1–3) and hours, and the interactions between these variables. Results Overall, the mean ± sem daily distances travelled by NSAID and TRAD reindeer did not differ (6.60 ± 0.67 km vs. 8.60 ± 1.54 km) but the days differed: reindeer travelled longer daily and hourly distances on the 1^st than the 3^rd day and TRADs travelled longer distances than NSAIDs during the first day after castration (11.67 ± 2.25 km vs. 7.08 ± 0.61 km), with no difference observed on the 2^nd or 3^rd day (10.19 ± 3.87 km vs. 6.59 ± 0.85 km and 5.35 ± 0.39 km vs. 6.17 ± 0.70 m, respectively). Day- and night-time distances did not differ on the 1^st day, but the daytime distances travelled on the 2^nd and 3^rd days were longer than during respective nights. The travelled daytime distances remained steady while night-time distances decreased. The daily rhythm was particularly broken with the more restless TRAD group. Conclusions Meloxicam may reduce restlessness in castrated reindeer in the wild for two days after castration. Further studies are needed on the use of analgesia and GPS collars for pain monitoring in freely grazing reindeer.