Effect of tolazoline on xylazine-ketamine-induced anesthesia in turkey vultures

Fifteen turkey vultures were each given xylazine (1 mg/kg of body weight, IM) and ketamine (10 mg/kg, IM). In 5 of the birds (controls), the mean (+/- SD) induction time was 5.4 +/- 1.0 minutes and the mean duration of anesthesia was 109.8 +/- 25.4 minutes. The remaining 10 vultures (test birds) were given tolazoline (15 mg/kg, IV) 45 minutes after administration of xylazine and ketamine. In the test birds, the mean induction time was 4.5 +/- 1.6 minutes and the mean duration of anesthesia was 49 +/- 2.1 minutes. After administration of tolazoline, the birds regained consciousness in 3.7 +/- 1.9 minutes and were standing with normal posture in 14.2 +/- 5.4 minutes. All birds remained moderately sedated yet ambulatory and responsive to stimuli for 30 to 60 minutes after tolazoline administration. Results indicated that tolazoline was useful in controlling the duration of xylazine-ketamine-induced anesthesia in turkey vultures.