Field immobilization of lions using disassociative anaesthetics in combination with sedatives

Abstract

SummaryZoletil (CI‐744) proved to be a useful drug combination for lions during 64 immobilizations. The duration of Zoletil immobilizations were dosage dependent, but the onset of immobilization was similar for both low and high dosages. These characteristics were pragmatic in that low dosages of Zoletil were used for the initial dose, which was delivered by dart‐syringe. This practice facilitated either a short duration of immobility, or the possibility of adding an additional dose by hand, which prevented the loss of large amounts of Zoletil in the case of a dart failure. Ketamine and xylazine were used on 120 lions at dosages of 7.5 and 3.5mgkg‐l, respectively, and antagonized with 3.9mg kg‐1 Tolazoline. Disadvantages of the ketamine/xylazine combination were the inability to use lower dosages for short periods of immobilization and the large volumes required. Midazolam served as a practical drug for the capture of retiring and unapproachable lions, and significantly increased trapping success. Additional notes are presented on the use of Ro 15–3505 as an antagonist for Zoletil immobilization in lions.