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

Abstract

A combination of tiletamine-zolazepam/xylazine (TZ/X) is effective in the chemical immobilization of white-tailed deer (Odocoileus virginianus); however, the lengthy duration of immobilization may limit its usefulness. From October to November 2002, 21 captive female deer were assigned randomly to an ␣ 2 antagonist treatment to reverse xylazine-induced sedation (seven does per group). All deer were given 220 mg of TZ (4.5Ϯ0.4 mg/kg) and 110 mg of X (2.2Ϯ0.2 mg/kg) intramuscularly (IM). Antagonist treatments were either 200 mg of tolazoline (4.0Ϯ0.4 mg/kg), 11 mg of atipamezole (0.23Ϯ0.02 mg/kg), or 15 mg of yohimbine (0.30Ϯ0.02 mg/kg) injected, half intravenously and half subcutaneously, 45 min after the IM TZ/X injection. In addition, 10 other deer (five per group) were immobilized as before and then given tolazoline (200 mg) after 45 min, with either a carrier (dimethyl sulfoxide [DMSO]) or carrier (DMSO) plus flumazenil (5 mg) to reverse the zolazepam portion of TZ. Mean times from antagonist injection until a deer raised its head were different for ␣ 2 antagonist treatments (Pϭ0.02). Times were longer for yohimbine (62.3Ϯ42.7 min) than for either atipamezole (24.3Ϯ17.1 min) or tolazoline (21.3Ϯ14.3 min). Mean times from antagonist injection until standing were not different (Pϭ0.15) among yohimbine (112.0Ϯ56.4 min), atipamezole (89.7Ϯ62.8 min), or tolazoline (52.6Ϯ37.2 min). A sedation score based on behavioral criteria was assigned to each deer every 30 min for 5 hr. On the basis of sedation scores, tolazoline resulted in a faster and more complete reversal of immobilization. Flumazenil treatment did not affect recovery.

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

“…The general average doses of X (2.95±1.09 mg/kg) used with success in this study were slightly higher than those reported by other authors (Janovsky et al, 2000;Read et al, 2001;Miller et al, 2004;Walter et al, 2005). The same applies to the X and Z dosing range.…”

“…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).…”

“…This aspect, recumbence and a mix of seasonal foods may explain the described ruminal meteorism. The choice of atipamezole as alpha2-antagonist to reverse the X effects is in accordance with many studies reporting this drug to be effective as an antagonist to X in wild animals (Anremo et al, 1993;Acrenaz, 1994;Caulkett 2001;Miller et al, 2004;Janicki et al, 2006). The difference in handling time (45 to 120 min) regarded the place in which the animals had been darted and the distance between same and the lairage stable.…”

“…During the last twenty years many studies have reported the efficacy and safety of alpha-2-adrenoceptor agonists in combination with general anaesthetic agents such as ketamine (K) or tiletamine-zolazepam (T-Z) in many species of deer: red deer (Cervus elaphus) in Europe (Jalanka and Roeken, 1990;Janovsky et al, 2000) and other countries (Millspaugh et al, 1995;Read et al, 2001;Walter et al, 2005), and white-tailed deer (Odocoileus virginianus) in the USA (Kilpatrick and Spohr, 1999;Miller et al, 2004). These combinations, alpha-2-adrenoceptor agonists and K or T-Z, are very well known and used, probably because they have shown the closest characteristics to the "ideal" immobilization drugs to date (McKenzie, 1993).…”

Atipamezole Attenuated Telazol/Xylazine-Induced Expression of C-Fos in Rat Thalamencephal and Cerebral Cortex

“…Hence, telazol as a sole immobilizing agent and in combination with xylazine is used to immobilize wildlife [2][3][4], cats [5], dogs [6], and livestock [7,8]. Telazol-xylazine has been used on several animal species including white-tailed deer [9], bighorn sheep [10], grizzly bears [11], raccoons [12], American martens [13], and martes pennanti [14]. Atipamezole is a potent and selective α 2 -adrenoceptor agonist with a competitive nature which can antagonize ketamine [15], reverse xylazine-ketamine anaesthesia in the Northern chamois [16], reverse medetomidine -ketamine and tiletamine-zolazepam restrained fi shers [17,18].…”