Abstract

Ketamine/xylazine combinations have long been used in large felids for routine surgical procedures. Even though studies have been carried out in multiple species on intravenous usage of this combination, there is a scarcity of reports on safe intravenous usage of the combination in large felids. Over a period of six months, eight captive Bengal tigers of different age categories were anesthetized with atropine sulfate/xylazine/ketamine combination intravenously for either surgical procedures or short-distance transportation. Food and water were withheld for 12 hours prior to the procedure in all of the tigers. Tigers were secured in a squeeze cage, and intravenous cannulation was carried out using either the dorsal or lateral coccygeal vein. Anesthesia was induced with an intravenous bolus dose of atropine sulfate (0.03 mg/kg) and xylazine (1.5 mg/kg) followed by ketamine (2 mg/kg). Overall induction time was 1–2 minutes, recumbency time without supplementation of ketamine was 35–49 minutes, and recovery time was 50–66 minutes. Depth of anesthesia was constantly observed with palpebral and pedal reflexes. During 2 surgical procedures when tigers showed recovery symptoms, ketamine was given intravenously (1 mg/kg) which prolonged the anesthesia for 20–36 minutes. Heart rate and respiratory rate decreased and remained constant during the entire process, but respiratory rate increased rapidly during the recovery process. The present study indicates that an atropine sulfate/xylazine/ketamine combination administered intravenously produces a safe and satisfactory anesthesia in captive Bengal tigers. Further studies to investigate various dosages or the substitution of other drugs for the combination are warranted.

Acknowledgements

We would like to thank the Executive Director of Bannerghatta Biological Park for his support during the study. We also thank range forest officers, veterinary assistants, animal keepers and zoo staff for their kind cooperation and support during the procedures involved in the study.