A Comparison of Carfentanil/Xylazine and Telazol®/Xylazine for Immobilization of White-Tailed Deer

Abstract

From October 2001 to January 2002, captive free-ranging white-tailed deer (Odocoileus virginianus) were immobilized with a combination of carfentanil citrate and xylazine hydrochloride. From this study, we selected a dose of carfentanil/xylazine for the purpose of comparing immobilization parameters and physiologic effects with those of a combination of tiletamine and zolazepam (Telazol ) and xylazine. Animals were initially given intramuscular injections of 10 mg xylazine and one of four doses of carfentanil (i.e., 0.5, 1.0, 1.5, and 2.0 mg). A carfentanil dose of 1.2 mg (xϮSDϭ23.5Ϯ3.2 g/kg) and 10 mg xylazine (0.2Ϯ0.03 mg/kg) were selected, based on induction times and previously published reports, to compare with a combination of 230 mg of Telazol (4.5Ϯ0.6 mg/kg) and 120 mg xylazine (2.3Ϯ0.3 mg/kg). Time to first observable drug effects and to induction were significantly longer for deer treated with carfentanil/xylazine than with Telazol /xylazine (PϽ0.01). Hyperthermia was common in deer immobilized with carfentanil/xylazine, but heart rate, respiration rate, and hemoglobin saturation were within acceptable levels. Degree of anesthesia of deer immobilized with Telazol /xylazine was superior to deer immobilized with carfentanil/xylazine. The combination of 120 mg of naltrexone hydrochloride and 6.5 mg of yohimbine hydrochloride provided rapid and complete reversal (1.9Ϯ1.1 min) of carfentanil/xylazine immobilization. Animals immobilized with Telazol /xylazine had long recovery times with occasional resedation after antagonism with 6.5 mg of yohimbine. The combination of carfentanil and xylazine at the doses tested did not provide reliable induction or immobilization of white-tailed deer even though drug reversal was rapid and safe using naltrexone and yohimbine.

Transmitter-equipped darts in a protocol for chemically immobilizing free-ranging red deer (Cervus elaphus) in Central Italy

“…Our standing times were a bit shorter than those of other authors (Miller et al, 2003;Miller et al, 2004;Walter et al, 2005), probably because of the administrated formula we used: two thirds IM and a third IV. This means of administration allows the animals reversed under wild conditions to immediately have good reactions and flight towards external stimuli (Schobert, 1987).…”

Pharmacokinetic study in pigs andin vitrometabolic characterization in pig- and human-liver microsomes reveal marked differences in disposition and metabolism of tiletamine and zolazepam (Telazol)

“…Telazol Õ injection is administered intramuscularly or intravenously and is approved for use in cats and dogs undergoing surgical procedures (Telazol Õ package insert; Pfizer Animal Health/Zoetis). This drug combination is also extensively used in veterinary research for inducing anesthesia and for immobilization of wild animals (Belant, 2004;Lin et al, 1993;Miller et al, 2003;Natalini et al, 2004;Stirling et al, 1989;Walter et al, 2005). The tiletamine analog ketamine and propofol are the most common induction agents for veterinary anesthesia in the United States and alfaxolone is used widely in Australia and Europe.…”

Effectiveness of Antagonists for Tiletamine-Zolazepam/Xylazine Immobilization in Female White-Tailed Deer

“…Therefore, TZ/X greatly facilitates the capture of white-tailed deer and is effective and safe when it is administered under field conditions (Kilpatrick and Spohr, 1999;Murray et al, 2000). One problem with TZ/X immobilization is the extended recovery time for deer (Millspaugh et al, 1995;Nielsen, 1999;Miller et al, 2003).…”

“…Mean weights (ϮSD) of the deer were 49.7Ϯ4.7 kg. Each deer was manually restrained in a squeeze chute and was given 220 mg of TZ (100 mg/ml; Fort Dodge Animal Health, Fort Dodge, Iowa, USA) and 110 mg of X (Cervizine; Wildlife Pharmaceuticals, Inc., Fort Collins, Colorado, USA) via intramuscular (IM) injection into the hindquarters (modified from Miller et al, 2003). Immediately after drug injection, deer were released into a 15ϫ20-m observation pen, and the times (min) to first noticeable drug effect, sternal recumbency, and lateral recumbency were recorded.…”