Abstract

Twenty-eight bighorn sheep were captured between September 2009 and December 2011 in Kananaskis Provincial Park, Alberta, Canada. Sheep were approached and darted on foot, or from a vehicle. A laser range finder was used to assess distance, and a dart rifle was used to deliver either a 3- or 5-ml dart containing medetomidine (0.16±0.04 mg/kg [mean±SD]) combined with ketamine (4.2±1.6 mg/kg). Induction time (9.8±9.4 min) was taken as the time from first dart placement to becoming recumbent. The animal was maintained in sternal recumbency, as much as possible. An arterial blood gas sample was obtained from the femoral or auricular artery, to determine oxygenation, ventilation and acid-base status. Samples were corrected for body temperature and analyzed immediately with a portable clinical analyzer. After 77±25 min, atipamezole (0.8±0.2 mg/kg) was administered intramuscularly. Time from atipamezole to standing was 3.4±1.7 min. Induction was smooth and controlled. Recovery was complete, with animals being able to negotiate steep terrain. The major side effect was hypoxemia, supplemental inspired oxygen is recommended.

Table 1. Arterial blood gas analysis, and vital signs in bighorn sheep anesthetized with medetomidine-ketamine. Data reported as mean ± standard deviation, and range