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.     

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.     

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.     

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.     

Immobilization of wild ocelots with tiletamine and zolazepam in southern Texas

Telazol was used to immobilize nine wild ocelots (Leopardus pardalis) captured in box-traps in southern Texas (USA) between May 1997 and April 1998. Mean (+/- SD) intramuscular dosage rate of 5.05 (+/- 0.76) mg/kg produced an induction time of 3.7 +/- 1.8 min. Duration of cataleptic anesthesia was 67.4 +/- 19.8 min and ocelots stood 50.0 +/- 30.7 min after emergence from cataleptic anesthesia. Ocelots recovered to their preinjection condition 129.7 +/- 28.8 min after first standing and 250.8 +/- 55.1 min after initial injection. We observed no adverse reactions to Telazol aside from minor loss of thermoregulatory control. Telazol administered at 5 mg/kg was an effective and safe immobilizing agent for wild ocelots.     

Anesthesia in female white-tailed deer using Telazol and xylazine

Thirty two free-ranging female white-tailed deer (Odocoileus virginianus) were anesthesized with varying Telazol and xylazine HCl combinations in Front Royal (Virginia, USA) between August 1992 and September 1992. All animals were caught in baited box traps, manually restrained, and hand injected with a combination of Telazol and xylazine administered intramuscularly. Deer received mean +/- SE dosages of 2.53+/-0.16 mg/kg Telazol and 0.69+/-0.05 mg/kg of xylazine. These dosages achieved a rapid and effective anesthetic plane for short-term procedures such as weighing, blood collection, and translocation. Eight of 32 deer (25%) required an intravenous (i.v.) supplement of ketamine HCl (100 mg) to maintain a safe plane of anesthesia. Ketamine supplementation provided an average of 11.8+/-2.0 min additional safe handling. Satisfactory reversals were achieved in all deer by administering yohimbine HCl 16 mg i.v. (dose range, 0.22 to 0.48 mg/kg) to all animals.     

Capture and immobilization of wild brown palm civets in Western Ghats

A mixture of 15 mg/kg body weight ketamine hydrochloride (KE) and 1.5 mg/kg body weight xylazine hydrochloride (XY) was used to successfully immobilize free-ranging brown palm civets (Paradoxurus jerdoni). Between March 1998 and June 1999, 10 immobilizations of 7 individuals were carried out in tropical rainforests of the Kalakad-Mundanthurai Tiger Reserve (India). Five males and two females were captured in Havahart live traps, using banana as bait. The mean dosage for the animals, whose weight (mean +/- SD) was 2.4 kg +/- 0.8 was 36.0 +/- 11.0 mg KE and 3.7 +/- 1.1 mg XY, administered intramuscularly. Mean time for lateral recumbency was 6.1 +/- 3.78 min (n = 10) and the mean time taken for complete recovery was 84.9 +/- 28.8 min (n = 9). Recovery was gradual and no fatalities or injuries occurred during the operation. The drug combination used was effective and has the potential for immobilizing other viverrids.     

Field immobilization of American martens (Martes americana) and short-tailed weasels (Mustela erminea).

Ketamine hydrochloride (KH) and a 5:1 combination of KH and xylazine hydrochloride (XH) were used successfully to immobilize short-tailed weasels (Mustela erminea) and American martens (Martes americana), respectively. Four adult male martens were intramuscularly injected with 30 to 82 mg/kg KH and 8.0 to 16.4 mg/kg XH. Three adult male short-tailed weasels were intramuscularly injected with 20.8 to 42.1 mg/kg KH. Mean (+/- SE) induction times for martens and short-tailed weasels were 1.8 +/- 0.2 min and 46 +/- 4.1 sec, respectively; recovery times were 100.4 +/- 19.3 min and 97.9 +/- 6.3 min, respectively. Heart rate was relatively constant among martens; however, respiration varied widely (21 to 122 breaths per minute). Marten body temperature decreased between 0 and 20 min post-recumbency. Short-tailed weasel heart rate and respiration decreased in response to sedation until slightly before arousal. Body temperature stabilized by 20 min post-recumbency. Two short-tailed weasels tremored slightly within 10 min of arousal. I conclude that KH and KH/XH are safe immobilizing agents for martens and short-tailed weasels, respectively.     

Immobilization of fishers (Martes pennanti) with ketamine hydrochloride and xylazine hydrochloride

A combination of 100 mg ketamine hydrochloride (KH) and 20 mg xylazine hydrochloride (XH) was used to immobilize fishers (Martes pennanti). Four adult males were intramuscularly injected a total of five times at dosages between 22.4 to 29.0 mg/kg KH and 4.1 to 6.6 mg/kg XH. Mean (+/- SE) induction time and arousal time were 3.3 +/- 0.5 min and 76.8 +/- 12.1 min, respectively. Respiration, heart rate, and body temperature in response to sedation appeared normal. A 5:1 mixture of KH-XH appears to be a safe immobilizing agent for fishers.     

Immobilization of white-tailed deer with telazol,ketamine, and xylazine,and evaluation of antagonists

Telazol–xylazine and ketamine–xylazine are versatile and safe drug combinations that are used frequently for chemical immobilization of cervids. Although neither combination consistently offers rapid induction and recovery, we hypothesized that a combination of Telazol, ketamine, and xylazine (TKX) would provide a safe and effective alternative for immobilization of white-tailed deer (Odocoileus virginianus). During a 2-stage study, we evaluated the effectiveness of yohimbine and tolazoline as alpha₂-adrenergic antagonists (2005–2006), and characterized the factors that affected chemical immobilization of male deer with a targeted dose of telazol (2.20 mg/kg), ketamine (1.76 mg/kg), and xylazine (0.44 mg/kg), using explosive-charged darts (2007–2010). During the first stage, we randomly assigned deer to antagonist treatments, including a control group that did not receive an antagonist (n = 8), a tolazoline (4 mg/kg) treatment (n = 16), and a yohimbine (0.11 mg/kg) treatment (n = 15). Recovery times were longer (P = 0.0013) for control (150.6 ± 21.7 min) and yohimbine (74.5 ± 13.1 min), compared with tolazoline (12.5 ± 12.3 min). Tolazoline resulted in faster and more complete recovery compared with the frequent incomplete antagonism and ataxia observed with yohimbine. During the second stage, 56 immobilization events (2007–2010) with TKX yielded a mean induction time of 7.8 minutes (SE = 0.44). Repeated-measures analyses indicated that induction and recovery were affected by body weight, with larger males taking longer to become recumbent (P = 0.08), but they recovered more rapidly (P = 0.003) following administration of tolazoline. Physiological parameters we measured under anesthesia were within normal ranges for white-tailed deer; however, initial temperature was higher (β = −0.86) for younger males (P = 0.014). Final physiological parameters were closely related to initial measurements, with rectal temperature being the most preserved (β = 0.90); heart and respiration rate declined (β < 0.60) during anesthesia. Our results indicate that TKX may be useful for chemically immobilizing white-tailed deer, and we recommend tolazoline as an antagonist for xylazine. © 2012 The Wildlife Society.     

Field immobilization of Molina's hog-nosed skunk (Conepatus chinga) using ketamine and xylazine

We injected 27 adult Molina's hog-nosed skunks (Conepatus chinga) intramuscularly by hand with ketamine hydrochloride (KH) and xylazine hydrochloride (XH) in the Pampas grassland of Argentina. Skunks were immobilized with a mean (±SD) dosage of 24.9±6.5 mg/kg KH and 1.9±0.6 mg/kg XH. The mean effective dosages of KH (27.6 mg/kg) and XH (1.7 mg/kg) were higher and lower, respectively, than those reported in skunks previously. Mean induction and recovery time were 5.3±1.9 min and 47.7±18.5 min, respectively. Hypothermia was the only problem detected in field immobilization and occurred in winter but did not appear to be associated with to drug doses. We conclude that KH/XH is a safe immobilizing drug combination for Molina's hog-nosed skunk.     

Evaluation of Telazol-xylazine as an anesthetic combination for use in Syrian hamsters.

The availability of safe parenteral anesthetics for use in Syrian hamsters is limited. We evaluated the effects of Telazol-xylazine (TZX) combinations with respect to anesthetic efficacy and potential for tissue damage. Two dose levels of the combination were administered by both the intraperitoneal (IP) and intramuscular (IM) routes. TZX by the IM route failed to consistently produce anesthesia and caused gross and histopathologic muscle lesions. IP administration of 20 mg/kg Telazol combined with 10 mg/kg xylazine was adequate for restraint purposes. IP administration of 30 mg/kg Telazol combined with 10 mg/kg xylazine produced a safe, reliable level of surgical anesthesia without evidence of gross or histopathologic lesions. There was no nephrotoxicity at either concentration of the anesthetic. A dose level of TZX that provides safe parenteral anesthesia in Syrian hamsters was determined.     

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.     

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.     

Physiological and behavioral responses of gray wolves (Canis lupus) to immobilization with tiletamine and zolazepam

We conducted a series of experiments to examine the efficacy of Telazol (TEL) for immobilization of captive gray wolves (Canis lupus). Ten wolves were immobilized with either 5 or 10 mg/kg TEL. There was no difference in induction time (6.5 +/- 0.8 versus 5.8 +/- 1.2 min; P = 0.63) between the two doses, but the time to initial arousal was longer for the higher dose (P = 0.0008). Wolves were again immobilized with 10 mg/kg TEL and upon initial arousal were given additional doses of either 5.0 mg/kg TEL or 2.5 mg/kg ketamine (KET) to maintain immobilization. Wolves given boosters of TEL had longer second recovery times than wolves given KET (P = 0.01). There were no differences in induction times or arousal times for wolves immobilized with TEL that had been reconstituted with sterile water and stored at 20 C for 30 days (P greater than or equal to 0.11) or 60 days (P greater than or equal to 0.27) when compared to immobilization times using fresh solution. Induction times for wolves given TEL reconstituted with water and propylene glycol and stored for 60 days at -9 C were longer (P less than 0.05) than such times for wolves given standard TEL, but time to initial arousal was unchanged (P greater than or equal to 0.44). There were no differences in heart rates (P = 0.36), blood pressures (P = 0.32), respiratory rates (P = 0.91), and rectal temperatures (P = 0.62) between the two TEL doses. Telazol was shown to be an effective and safe immobilizing agent for gray wolves.     

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.     

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).     

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.     

Immobilization of mule deer with thiafentanil (A-3080) or thiafentanil plus xylazine

We evaluated thiafentanil oxalate (A-3080) for the immobilization of mule deer (Odocoileus hemionus) under laboratory and field conditions. In a crossover experiment comparing recommended (0.1 mg/kg) and 2x recommended thiafentanil doses in captive deer, both produced rapid induction and immobilization. Mean induction was shorter (P = 0.013) for the 2x group (1.9 vs. 3 min); mean reversals for both groups were rapid (recommended = 0.9 min after naltrexone injection; 2x = 1 min) and did not differ (P = 0.29). Six free-ranging mule deer were immobilized with 7 mg thiafentanil and four with 10 mg; mean induction was 2.3 min for both groups (95% confidence interval [CI]: 7 mg, 1.2-3.4; 10 mg, 1.9-2.8), and mean reversal was <1 min for both groups. Of 165 free-ranging deer darted with various combinations of thiafentanil and xylazine, we successfully immobilized 148 (90%). Mean induction ranged from 2.1 to 4.9 min for different drug combinations. Reversals were not compared because naltrexone and yohimbine doses varied, but overall mean reversal was 1.9 min (95% CI, 1.7-2.1 min) after injection of naltrexone and yohimbine intravenously (i.v.); naltrexone:thiafentanil ratios ranging from 10:1 to 43:1 provided mean recoveries ranging from 1.5 to 2.3 min. All 25 deer fitted with radio collars were alive at 30 days postcapture. On the basis of overall reliability and effectiveness, drug volumes, and ease of handling drugged animals, we recommend using a combination of 10-12 mg thiafentanil (0.15-0.2 mg/kg) and 100 mg xylazine to immobilize mule deer; immobilization can be effectively reversed with 100 mg naltrexone or more and 15 mg yohimbine or more i.v. Where feasible, we also recommend the use of transmitter darts when immobilizing mule deer with opioids in order to maximize recovery of darted deer and to ensure that missed darts are found.     

Reversal by tolazoline hydrochloride of xylazine hydrochloride-ketamine hydrochloride immobilizations in free-ranging desert mule deer

We captured 10 free-ranging desert mule deer (Odocoileus hemionus crooki) (five males and five females) by net-gun from a helicopter and immobilized them with xylazine hydrochloride (HCl) (100 mg) and ketamine HCl (300 to 400 mg) injected intramuscularly. Arousal and ambulation times were 13.9 +/- 4.2 and 14.3 +/- 4.2 min in eight deer injected intravenously with tolazoline HCl (3.0 mg/kg). We observed a curvilinear relationship (R = 0.50, P less than 0.01) between rectal temperature and time after induction of anesthesia. Mean peak temperature (41.4 C) occurred at 23.7 +/- 3.2 min postinduction and was greater (P less than 0.01) than the mean temperature measured initially (40.8 C). Heart and respiratory rates (108 beats/min and 75 breaths/min) were elevated prior to immobilization. Mean heart rate increased (P less than 0.05) from 90 +/- 9 beats/min in anesthetized deer to 120 +/- 13 beats/min after tolazoline HCl injection. A 20% capture-related mortality rate suggests this combination of physical and chemical capture has serious limitations. Captive deer permitted to recover from xylazine HCl-ketamine HCl immobilization without a reversal agent were able to walk in 290 +/- 79 min.