Evaluation of Carfentanil and Xylazine for Immobilization of White-tailed Deer

From October 2001 until January 2002 captive wild white-tailed deer (Odocoileus virginianus) held at the University of Georgia Daniel B. Warnell School of Forest Resources Whitehall Deer Research Facility were immobilized with a combination of carfentanil (carfentanil citrate) and xylazine (xylazine hydrochloride) to 1) determine and evaluate an optimum and safe dose for carfentanil/xylazine in white-tailed deer and 2) compare immobilization parameters and physiological effects of carfentanil/xylazine to Telazol®/xylazine. Animals were given intramuscular injections of 10 mg of xylazine and one of four different levels of carfentanil 0.5, 1.0, 1.5, and 2.0 mg. A carfentanil dose of 1.2 mg (mean = 23.0 μg/kg) and 10 mg xylazine (mean = 0.19 mg/kg) was selected to compare with a combination of 230 mg of Telazol® (mean = 4.41 mg/kg) and 120 mg xylazine (mean = 2.3 mg/kg) based on induction times and previously published reports. Time until first drug effects and time until deer dropped to the ground without rising were significantly longer in deer treated with carfentanil/xylazine than Telazol®/xylazine (p