Relative efficiency of succinylcholine, xylazine, and carfentanil/xylazine mixtures to immobilize free-ranging moose

We compared the efficiency of succinylcholine chloride, xylazine hydrochloride and carfentanil/xylazine mixtures in immobilizing 364 free-ranging moose (Alces alces) between 1987 and 1997 in Québec (Canada). With succinylcholine chloride (0.070, 0.062, 0.051 mg/kg of estimated body weight for calves, juveniles and adults), 63% of the 252 immobilization attempts led to complete immobilization and marking, whereas 7% of the darted animals died of respiratory paralysis during handling. The moose took an average of 13 min to lay down after darting (down time). Injection of xylazine (3.67-4.22 mg/kg) permitted sedation (the animal laid down but got up again when approached) or complete immobilization in 78% of the 40 darted adult moose, the mean down time being 8.7 min. No mortality was noted with this drug but 58% of the marked animals were only sedated. The use of RX821002A (0.058 mg/kg) as an antagonist, permitted a mean recovery time of 2.8 min after intravenous injection. With the carfentanil/xylazine mixtures (0.0071 and 0.181 mg/kg), 96% of the immobilization trials (n = 72) led to complete (88%) or partial (8%) immobilization, but 6% of the moose died several days after capture. The mean down time was 6.6 min, and injection of naltrexone (0.709 mg/kg) antagonized the effect of the immobilizing agent within 3.7 min. The respiratory rate was higher (P < 0.05) among moose immobilized with xylazine (35/min) than among those immobilized with carfentanil/xylazine mixtures (19/min) but this variation could be related to a longer pursuit time (z = 3.60; P < 0.01) and higher stress levels during handling. Rectal temperature also was higher with xylazine but the difference was small (39.7 vs. 39.3, P = 0.03) and did not differ significantly between the sexes (P > 0.05). Considering loss of materials and helicopter flight time due to non-successful marking trials, carfentanil/xylazine mixtures were the least expensive ($333 Cdn/animal).     

A comparison of carfentanil/xylazine and Telazol/xylazine for immobilization of white-tailed deer

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 (x +/- SD = 23.5 +/- 3.2 microg/kg) and 10 mg xylazine (0.2 +/- 0.03 mg/kg) were selected, based on induction times and previously published reports, to compare with a combination of 230 mg of Telazol (4.5 +/- 0.6 mg/kg) and 120 mg xylazine (2.3 +/- 0.3 mg/kg). Time to first observable drug effects and to induction were significantly longer for deer treated with carfentanil/xylazine than with Telazol/xylazine (P < 0.01). 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 (1.9 +/- 1.1 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-tailel (leer even though drug reversal was rapid and safe using naltrexone and yohimbine.     

Chemical immobilization of free-ranging North American bison (Bison bison) in Badlands National Park, South Dakota

Twenty-six free-ranging North American bison (Bison bison) (22 adult bulls, one yearling male and three adult females) were immobilized using a combination of carfentanil and xylazine. For carfentanil the dose range (mean +/- SD) was 1.8-5.0 micrograms/kg (2.4 +/- 0.7 micrograms/kg) and for xylazine 0.004-0.125 mg/kg (0.07 +/- 0.03 mg/kg). Induction time (mean +/- SE) was 14.2 +/- 2.9 min (median 8 min), while the total mean reversal time after administration of a narcotic antagonist was 9.0 +/- 1.4 min (median 8 min). Only one animal that received the highest initial dose of carfentanil (2.5 mg) showed evidence of becoming "re-narcotized." Five animals required two or more doses of carfentanil before becoming immobilized. Overall, small volumes of drug used (mean = 0.62 ml for carfentanil, 0.53 ml for xylazine) enabled the use of 1 to 2 ml darts, increasing both accuracy and impact safety. Darting success approached 100%.     

Prolonged and multiple immobilizations of the southern elephant seal using ketamine hydrochloride-xylazine hydrochloride or ketamine hydrochloride-diazepam combinations

Thirty seven southern elephant seals (Mirounga leonina) were singularly or repeatedly immobilized with combinations of ketamine hydrochloride (HCl) and xylazine HCl or ketamine HCl and diazepam. Atropine sulphate was included in the drug combinations. To permit experimental procedures the seals were immobilized for periods of 30-330 min. The mean induction dose of ketamine HCl was 8.71 +/- 0.25 mg/kg (mean +/- SE). The mean induction time was 16.02 +/- 2.62 min. For the elephant seals immobilized for periods in excess of 180 min, the mean dose of ketamine HCl used per hr was 3.31 +/- 0.13 mg/kg/hr and the mean dose of ketamine HCl used per hr postinduction was 1.31 +/- 0.15 mg/kg/hr. The mean dose of diazepam used was 0.09 +/- 0.01 mg/kg and the mean dose of xylazine HCl was 0.41 +/- 0.01 mg/kg. Elephant seals were weighed on 20 occasions (weight range: 897-1,932 kg) and the relationship between standard length and weight was found to be: Weight = 9.98 length - 2,317.63 (r2 = 0.724). Adverse reactions to seals immobilized only once or twice were not observed. Two seals immobilized on three occasions developed abscesses at the site of injection.     

Evaluation of xylazine hydrochloride as the sole immobilizing agent in moose and caribou--and its subsequent reversal with idazoxan

Xylazine hydrochloride was used as the sole immobilizing agent in moose and caribou. The animals were free-ranging and immobilization was accomplished from a helicopter using powered darts. Following a period of immobilization during which radiotelemetry collars were fitted, the animals were revived using idazoxan (RX 781094) or its methoxy analogue RX 821002. Xylazine was administered at dose rates of approximately 3.0 mg/kg and 5.0 mg/kg to the moose and caribou, respectively. Moose received 430 +/- 27 mg of xylazine and a mean dose of 10 mg idazoxan (RX 781094). Caribou received 485 +/- 30 mg xylazine and a mean dose of 4 mg idazoxan (RX 821002). This technique gave adequate immobilization with rapid recovery of consciousness in both species.     

Butorphanol/xylazine/ketamine immobilization of free-ranging Baird's tapirs in Costa Rica

Cardiopulmonary effects and the utility of a butorphanol/xylazine/ketamine combination were evaluated during twenty immobilizations of sixteen Baird's tapirs (Tapirus bairdii) between March 1996 and January of 1998 in Corcovado National Park (Costa Rica). The animals were attracted to a bait site and darted from tree platforms. The tapirs were estimated to weigh between 200 to 300 kg. Actual weights of three tapirs taken at later dates fell within the estimated range. A butorphanol, 48+/-1.84 (x +/- SE) mg/animal IM, and xylazine, 101+/-2.72 mg/animal IM, combination was used to immobilize the animals. In some instances, ketamine was used either IM or IV at 187+/-40.86 mg/animal to prolong the immobilization period in addition to the butorphanol/xylazine combination. Naltrexone was used IM to reverse butorphanol at 257+/-16.19 mg/animal. Either yohimbine, 34+/-0.61 or tolazoline at 12+/-10.27 mg/animal, was used to reverse xylazine. The mean time from dart impact to first visible effect was 4.63+/-0.50 min (x +/- SE). Mean time to sternal recumbency was 12.21+/-1.08 min. Mean time the tapirs were immobilized was 45.63+/-3.6 min. Mean time to return to sternal recumbency and standing in animals that received yohimbine and naltrexone was 3.16+/-1.06 and 5.33+/-1.45 min, respectively. Mean time to return to sternal recumbency and standing in animals that received tolazoline and naltrexone was 1.57+/-0.39 and 3.14+/-0.51 min, respectively. Cardiopulmonary parameters including heart rate, respiratory rate, body temperature, electrocardiogram, percent oxygen satoration, and indirect blood pressure were recorded. Arterial blood gas analysis was performed on four animals. A mild degree of hypoxemia was evidenced by low arterial oxygen saturations. Five of 14 (36%) animals measured had oxygen saturations below 90%. Bradycardia (heart rates <45 BPM) was an expected finding in 11 (55%) immobilizations. Induction, recovery and muscle relaxation of each immobilization was graded. Premature arousal, which occurred in six (30%) animals, was the only problem associated with the immobilizations. Butorphanol/xylazine is a recommended protocol for immobilization of calm, free-ranging tapirs lasting less than 30 min. Supplemental intravenous administration of ketamine is recommended for longer procedures. Nasal insufflation of oxygen is recommended.     

Immobilization of gray wolves (Canis lupus) with sufentanil citrate

Gray wolves (Canis lupus) were immobilized with 0.5 mg/kg xylazine plus 7.5 micrograms/kg of either sufentanil (n = 8), etorphine (n = 8), or carfentanil (n = 2). Drug doses used in this study were selected to provide consistency for comparison and are not recommended doses for effective immobilization of wolves. Induction times were similar among groups (11.9 +/- 1.0 min). Thirty min after induction, wolves were given either 0.5 mg/kg naloxone hydrochloride plus 0.15 mg/kg yohimbine hydrochloride or saline only intravenously. Arousal times for wolves given naloxone and yohimbine (1.2 +/- 0.1 min) were shorter than wolves given saline (35.5 +/- 6.4 min). Respiratory rates were similar among the three drug groups (6.9 +/- 1.0 breaths/min). One animal given sufentanil then saline was found dead 108 min after induction. Presumptive diagnosis was renarcotization and hypothermia. Results indicated that sufentanil is an effective opioid immobilizing agent for gray wolves.     

Efficacy of immobilizing free-ranging elk with Telazol and xylazine hydrochloride using transmitter-equipped darts

From January 1999 to April 2002, 14 free-ranging elk were darted with a mixture of Telazol reconstituted with xylazine hydrochloride (HCl) in a forested habitat in southwestern Oklahoma and north-central Arkansas. Elk were darted from ground blinds, tree stands, or a vehicle at distances of 14-46 m and were recovered 37-274 m from the dart site. Elk were located using radiotelemetry with 3-cc disposable Pneu-dart transmitter darts. Mean+/-SD dose of Telazol and xylazine HCl was 590+/-192 mg/ml and 276+/-153 mg/ml, respectively, and mean time to standing after injection of reversal agent was 27 min (range: 1-65 min). The combination of Telazol and xylazine HCl successfully immobilized free-ranging elk, and transmitter-equipped darts permitted successful location of sedated elk by two people in areas of dense forest cover. The dose required to sedate elk appeared to vary depending on physiology and behavior, but no drug-induced mortality occurred despite the wide variance in the doses administered. We recommend 500 mg Telazol reconstituted with 300 mg xylazine HCl as an initial dose for a >or=200 kg elk. If needed to achieve full sedation, up to 3 additional ml of the mixture may be administered without adverse effects.     

Rapid reversible immobilization of feral stallions using etorphine hydrochloride, xylazine hydrochloride and atropine sulfate

Forty-eight newly captured free-ranging feral stallions (Equus caballus) from two different locations and six captive stallions were immobilized using combinations of etorphine hydrochloride, xylazine hydrochloride and atropine sulfate with or without acepromazine. Six animals were immobilized twice, 1 mo apart. The drugs were administered either intramuscularly (n = 13) or intravenously (n = 44). Mean immobilization time (+/- SE) after intravenous (i.v.) injection of etorphine, xylazine and atropine was 55 +/- 4 sec (range 20 to 185 sec) compared to 708 +/- 131 sec (range 390 to 1,140 sec) for intramuscular (i.m.) injection. Immobilization was reversed with i.v. administration of 3 to 11 mg diprenorphine hydrochloride and 16 to 24 mg yohimbine hydrochloride. Average time from administration to standing and walking was 86 +/- 7 sec (n = 55). Reversal of etorphine-induced immobilization with an amount of diprenorphine equal to the etorphine and administered i.v. was as effective as a 2:1 ratio of diprenorphine to etorphine. Acepromazine had no effect on induction time, but decreased relaxation after immobilization and prolonged ataxia after reversal of the etorphine and xylazine. Eight free-ranging horses were immobilized in 708 +/- 132 sec by darting with 5.5 mg etorphine, 1,300 mg xylazine and 15 mg atropine from a helicopter. Three animals died during the study: one immediately after reversal of an i.v. administration, one from a broken neck during induction from darting, and one was found a week later at the site of darting.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of the anaesthetic/tranquillizer treatments on selected plasma biochemical parameters in NZW rabbits

In order to assess the response of plasma biochemical parameters to anaesthesia, 40 New Zealand White (NZW) rabbits were assigned to four treatment groups (n = 10): control (1 ml i.v. saline solution), fentanyl-droperidol (FD) (0.4 ml/kg s.c. of 'thalamonal' solution; 2.5 mg/ml droperidol, 0.05 mg/ml fentanyl), ketamine (K) (10 mg/kg i.v.) with either xylazine (X) (3 mg/kg i.v.) or diazepam (D) (2 mg/kg i.v.). Blood samples were obtained from the central ear artery at six time points: before injection, and at 10, 30, 60, 120 min and 24 h after injection of the anaesthetics/saline. Plasma ALT, AST, ALP, GGT, BUN, creatinine, phosphate and potassium levels were measured by the Hitachi 747 autoanalyser. The administration of K-X increased (P < 0.05) plasma ALT (from 11.4 +/- 0.9 to 20.2 +/- 1.7 IU/l, at 10 min), AST (from 10.5 +/- 3.3 to 34 +/- 2.1 IU/l, at 120 min), BUN (from 17.2 +/- 0.9 to 25.8 +/- 1.8 mg/dl, at 60 min) and creatinine concentrations (from 1 +/- 0.1 to 1.6 +/- 0.2 mg/dl, at 10 min). After K-D administration, we observed an increase (P < 0.05) in plasma ALT (from 11.4 +/- 0.9 to 20.2 +/- 1.1 IU/l, at 10 min), AST (from 11.4 +/- 1.6 to 28 +/- 3.7 IU/l, at 10 min), BUN (from 15.8 +/- 0.8 to 30 +/- 1.5 mg/dl, at 10 min) and creatinine levels (from 1 +/- 0.08 to 2.2 +/- 0.2 mg/dl, at 120 min). No significant changes were seen in the FD group. We conclude that K-X and K-D may affect plasma concentration of select serum enzymes and biochemical parameters. These results should be taken into account when blood samples are evaluated in treated rabbits.     

Acute Thermal and Stress Response in Moose to Chemical Immobilization

Management and research of moose (Alces alces) in Alaska, USA, often require chemical immobilization; however, moose may be prone to capture-induced hyperthermia while immobilized. We chemically immobilized moose with carfentanil citrate and xylazine hydrochloride to measure rump fat depth, collect blood and fecal samples, and to deploy modified vaginal implant transmitters and global positioning system (GPS)-collars for recording body temperature and movement during and after the chemical immobilization. We predicted wild moose pursued and captured from a helicopter would have elevated body temperature at time of capture, whereas body temperature would remain stable in hand-raised captive moose not pursued and only hand-injected for immobilization. Additionally, we expected post-capture body temperature would be a function of activity, time immobilized, and ambient temperature. As predicted, body temperature of wild moose was elevated 1 hour after capture (38.9°C, 95% CI = 38.7–39.1°C) but returned to baseline levels within 3 hours (38.0°C, 95% CI = 37.9–38.1°C); however, body temperatures then rose above baseline levels and remained elevated 12–48 hours post-capture when movement rates were also elevated. Body temperatures in captive moose were not elevated 1-hour post-immobilization (37.9°C, 95% CI = 37.8–38.0°C). Body temperatures of wild moose were positively related to cortisol levels at time of capture. Two moose that died after immobilization had initial body temperatures similar to other immobilized moose; however, their body temperature began to rise at 17 hours and 40 hours post-immobilization. Our study provides evidence that chemical immobilization affects body temperature and movement of wild moose up to 48 hours after capture, possibly as a result of renarcotization from carfentanil citrate. With advancements in technology, we recommend fine-scale GPS data (<1-hr fix rates) and continuous body temperature be evaluated to detect evidence of renarcotization during and after opioid-based captures of northern ungulates. © 2020 The Wildlife Society.     

Sufentanil and xylazine immobilization of Rocky Mountain elk

From October 2009 through July 2010, five captive, 3-yr-old, female Rocky Mountain elk (Cervus elaphus) and nine free-ranging elk (one male, eight female) were immobilized with 0.1 mg/kg sufentanil plus 0.5 mg/kg xylazine which was antagonized with 1 mg/kg naltrexone and 2 mg/kg tolazoline. Induction and recovery times averaged 4.9 ± 0.3 min and 3.9 ± 0.4 min, respectively. Physiologic and blood gas parameters as well as bispectral index (BIS) were measured on the captive elk every 10 min for 30 min. Immobilization induced profound hypoxemia via hypoventilation and ventilation-perfusion mismatching as demonstrated by depressed partial pressure of arterial oxygen (P(a)O(2)) and increased partial pressure of arterial carbon dioxide (P(a)CO(2)). The only values to significantly (P<0.05) change over time were base excess (BE), bicarbonate (HCO(3)), and lactate. Bispectral index is a measure of anesthetic depth. The average BIS value over the 30 min period (59.1 ± 2.4) was higher than the BIS value at the approximate point where elk lose consciousness, which indicated that this drug combination produced neuroleptanalgesia but not general anesthesia. Sufentanil and xylazine provided effective remote immobilization in elk and could be substituted for carfentanil or thiafentanil and xylazine should the need arise.     

Xylazine hydrochloride-ketamine hydrochloride immobilization of wolves and its antagonism by tolazoline hydrochloride

Fourteen wolves (Canis lupus L.) were singularly or repeatedly immobilized with 30 mg xylazine hydrochloride (HCl) and 400 mg ketamine HCl. Mean induction time was 5.3 +/- 4.6 min (mean +/- SD). Administration of 8.0 mg/kg tolazoline HCl as an antagonist significantly reduced immobilization times from 148.0 +/- 52.7 to 47.9 +/- 8.9 min (F = 63.69, df = 1,17, P less than 0.05). The average times from injection to ambulation for 2.0, 4.0, and 8.0 mg/kg tolazoline HCl were 35.2 +/- 31.8, 18.5 +/- 11.7, and 10.2 +/- 9.1 min. Tolazoline HCl increased heart rates significantly (P less than 0.001) from 75 +/- 14 to 120 +/- 23 beats/min, reversing a xylazine HCl-induced bradycardia. Respiratory rates also increased significantly (P less than 0.01) after tolazoline HCl injection from 19 +/- 7 to 28 +/- 8 breaths/min. Immobilization resulted in an initial hypertension which was normalized after tolazoline HCl administration. One female wolf had a single sinoatrial block within 1 min of receiving tolazoline HCl. Tolazoline HCl appears to be an effective antagonist for xylazine HCl-ketamine HCl immobilization of wolves.     

Cardiovascular and behavioral responses of gray wolves to ketamine-xylazine immobilization and antagonism by yohimbine

Adult wolves (Canis lupus) were immobilized with 6.6 mg/kg ketamine hydrochloride (KET) and 2.2 mg/kg xylazine hydrochloride (XYL) administered intramuscularly. Induction time was 4.6 +/- 0.3 min (mean +/- SE). Immobilization resulted in significant bradycardia and hypertension (P less than 0.05). Twenty min after induction, the wolves were given 0.05-0.60 mg/kg yohimbine hydrochloride (YOH). Yohimbine given intravenously produced dose-related increases in heart rate (HR) with doses greater than 0.15 mg/kg resulting in extreme tachycardia (greater than 300 bpm). All doses of YOH caused a temporary decrease in mean arterial blood pressure (MABP) with some individual animals manifesting profound hypotension (less than 30 torr) at doses greater than 0.15 mg/kg. Increasing the dose of YOH above 0.15 mg/kg did not significantly decrease either arousal or ambulation times. Administering YOH at 40 or 60 min after induction resulted in decreased arousal and ambulation times. Stimulation by weighing and taking repeated blood samples during anesthesia did not shorten arousal times. We recommend that wolves immobilized with XYL-KET be antagonized with doses of YOH less than 0.15 mg/kg.     

Immobilization of Himalayan tahr with a xylazine-ketamine mixture and reversal with atipamezole under field conditions

Twenty-nine free-ranging Himalayan tahr (Hemitragus jemlahicus) were darted in the Sagarmatha National Park (Nepal) using different combinations of xylazine and ketamine. Animals in Group 1 (n = 4) received a mean xylazine-ketamine dose of 2.77 +/- 0.99 mg/kg xylazine plus 3.32 +/- 0.19 mg/kg ketamine in males and 2.39 +/- 0.10 mg/kg xylazine plus 4.29 +/- 0.17 mg/kg ketamine in females. Animals in Group 2 (n = 25) received a mean xylazine-ketamine dose of 1.70 +/- 0.41 mg/kg xylazine plus 3.06 +/- 0.74 mg/kg ketamine in males and 1.82 +/- 0.29 mg/kg xylazine plus 3.29 +/- 0.52 mg/kg ketamine in females. No anesthetic-related mortality was recorded. Anesthesia was reversed by a standard dose of 11 mg/animal of atipamezole administered by intramuscular injection. Although all anesthetic dosages immobilized free-ranging tahr successfully, a quick and smooth recovery was obtained (11.1 +/- 5.6 min) only with the dosages of Group 2.     

Field immobilization of bighorn sheep with xylazine hydrochloride and antagonism with idazoxan

Xylazine hydrochloride was used to immobilize 124 Rocky Mountain bighorn sheep (Ovis canadensis canadensis) between 1983 and 1988. Doses of xylazine for free-ranging lambs ranged from 70 to 130 mg with amounts increasing with lamb age. Average doses for 11 free-ranging adult males and 21 adult females darted from the ground were (means +/- SE) 363 +/- 16 and 251 +/- 7 mg, respectively. Adult females captured in "Stevenson's " box traps (n = 7) could be immobilized with significantly (P less than 0.001) less xylazine (93 +/- 9 mg) than free-ranging females but had similar induction times. Long recovery times associated with xylazine immobilization were eliminated with the intravenous administration of idazoxan (RX 781094) at an approximate dosage of 0.1 mg/kg. Eighteen sheep given idazoxan appeared fully recovered within 3 min of injection (means +/- SE = 1.2 +/- 0.2 min). Four mortalities (three lambs, one yearling male) (3% of total) occurred before idazoxan was available for trial.     

Yohimbine hydrochloride reversal of ketamine hydrochloride and xylazine hydrochloride immobilization of Bengal tigers and effects on hematology and serum chemistries

Six bengal tigers (Panthera tigris tigris) were immobilized five times at 2-wk intervals with ketamine hydrochloride (ketamine) and xylazine hydrochloride (xylazine) mixtures at different dose levels. Hematology and serum chemistry analyses on blood samples collected at each immobilization remained normal during the study. There were acute changes in hematocrit, chloride, potassium, glucose, and bilirubin as a function of xylazine dose level. The effect of yohimbine hydrochloride (yohimbine) on the depth and duration of immobilization was evaluated in a crossover design with every animal serving as its own control at each dose. Administration of yohimbine resulted in recovery of the animals within 4-8 min in contrast to greater than 60 min with no yohimbine treatment. There were no adverse effects noted with the yohimbine treatment and the tigers did not exhibit a relapse over the next 24 hr. Yohimbine at a dose of 5-15 mg per adult tiger provided effective reversal of 50-150 mg of xylazine per tiger.     

Tiletamine-zolazepam-xylazine immobilization of American marten (Martes americana)

The effectiveness of tiletamine-zolazepam (Telazol) and xylazine as an immobilizing combination for American martens (Martes americana) was evaluated. Fifteen martens were intramuscularly injected on 19 occasions using a 3:2 mixture of tiletamine-zolazepam (3.2+/-0.6 mg/kg [mean +/- SD]) and xylazine (2.1+/-0.4 mg/kg) at Pictured Rocks National Lakeshore, Michigan (USA) during May to October 2002-2003. Mean induction time was 2.5+/-1.8 min; mean recovery time was 70.8+/-31.9 min. There was no relation between the amount (mg/kg) of tiletamine-zolazepam-xylazine injected and induction (r(2)=0.08, P=0.26). However, there was an inverse relation (r(2)=0.28, P<0.01) between dosage and time to first effect of immobilants. Time to recovery increased (r(2)=0.21, P=0.05) with increased dosage. Mean heart rate, respiratory rate, and body temperature declined through 10 min postinduction (P<0.05). No mortality occurred and no short-term adverse effects were observed in recaptured individuals. In conclusion, a 3:2 mixture of tiletamine-zolazepam/xylazine is a safe and effective immobilizing agent for martens when conducting non-surgical field procedures. Immobilizing martens with 4.2 mg/kg tiletamine-zolazepam and 2.8 mg/kg xylazine should provide < or =30 min of handling time and allow full recovery in about 70 min.     

Tiletamine-zolazepam-xylazine immobilization of fishers (Martes pennanti)

The effectiveness of tiletamine plus zolazepam (Telazol) and xylazine as an immobilizing combination for fishers (Martes pennanti) was evaluated. Ten fishers were intramuscularly injected using a 5:3 mixture of Telazol (2.9+/-0.6 mg/kg [mean+/-SD]) and xylazine (2.1+/-0.4 mg/kg) at Pictured Rocks National Lakeshore, Michigan (USA) during May to October, 2001-05. Mean induction time was 4.7+/-4.4 min; mean recovery time was 94.6+/-46.0 min. There was no relationship between the amount (mg/kg) of Telazol-xylazine injected and time to first effect of immobilants, dosage and time to induction, or between dosage and time to recovery. Mean heart rate remained constant through 20 min postinduction. Respiratory rate and body temperature declined through 10 and 20 min postinduction, respectively. No mortality occurred and no adverse effects were observed in individuals up to 19 mo later. It was concluded that a 5:3 mixture of Telazol-xylazine is a safe and effective immobilizing agent for fishers when conducting nonsurgical field procedures. Immobilizing fishers with 6-7 mg/kg of the combination (3.8-4.4 mg/kg Telazol and 2.3-2.6 mg/kg xylazine) should provide > or =30 min of handling time and allow full recovery in < 90 min.     

Field immobilization of raccoons (Procyon lotor) with Telazol and xylazine

The effectiveness of tiletamine plus zolazepam (Telazol) and xylazine was evaluated as an immobilizing combination for raccoons (Procyon lotor). Fifteen raccoons were injected intramuscularly with a 3:2 mixture of Telazol (3.2+/-0.6 mg/kg [mean+/-SD]) and xylazine (2.1+/-0.4 mg/kg) at Pictured Rocks National Lakeshore, Michigan, USA, during May-October, 2001-03. Mean induction time was 4.8+/-3.8 min; mean recovery time was 128.5+/-48.4 min. No linear relationships were found between the amount (mg/kg) of Telazol-xylazine injected and induction (r2 = 0.06, P = 0.40) or recovery times (r2 = 0.01, P = 0.78). Mean heart rate, respiratory rate, and body temperature declined through 20 min after induction (P< 0.05). No mortality occurred and no short-term adverse effects were observed in recaptured individuals. I conclude that a 3:2 mixture of Telazol-xylazine is a safe and effective immobilizing agent for raccoons when conducting nonsurgical field procedures. Immobilizing raccoons with Telazol at 3 mg/kg and xylazine at 2 mg/kg should provide up to 60 min of handling time and usually allow full recovery in about 120 min.