Immobilization of California sea lions using medetomidine plus ketamine with and without isoflurane and reversal with atipamezole

The use of medetomidine and ketamine, alone and in combination with isoflurane, with atipamezole reversal was evaluated for immobilizing 51 California sea lions (Zalophus californianus) for a variety of medical procedures at a rehabilitation center in northern California (USA) between May 1997 and August 1998. Animals were given 140 microg/kg medetomidine with 2.5 mg/kg ketamine intramuscularly. Mean (+/-SD) time to maximal effect was 8+/-5 min. At the end of the procedure, animals were given 200 microg/kg atipamezole intramuscularly. Immobilization and recovery times were, respectively, 25+/-12 and 9+/-7 min for 35 animals maintained with medetomidine and ketamine alone and 58+/-30 and 9+/-9 min for 16 animals intubated and maintained with isoflurane. No mortalities occurred as a result of the immobilizations. Disadvantages of the medetomidine and ketamine combination included a moderate variation in time to maximal effect and plane of sedation, a large injection volume and high cost. However, this combination offers safe and reversible immobilization that can be easily administered by the intramuscular route and that produces a plane of anesthesia that is sufficient to carry out most routine diagnostic procedures.     

Use of medetomidine-zolazepam-tiletamine with and without atipamezole reversal to immobilize captive California sea lions

From June 1998 to August 1999, 39 California sea lions (Zalophus californianus) were immobilized at a rehabilitation center in northern California (USA) using medetomidine plus zolazepam and tiletamine (MZT), alone and in combination with isoflurane, with atipamezole reversal. Animals were given 70 microg/kg medetomidine with 1 mg/kg of a 1:1 solution of tiletamine and zolazepam intramuscularly. Mean (+/-SD) time to maximal effect was 5+/-3 min. At the end of the procedure, animals were given 200 microg/kg atipamezole intramuscularly. Immobilization and recovery times were, respectively, 28+/-18 and 9+/-7 min for 15 animals maintained with MZT alone and 56+/-47 and 9+/-6 min for 18 animals intubated and maintained with isoflurane. One mortality occurred during anesthesia. Other disadvantages of the MZT combination included some prolonged ataxia, weakness and disorientation during recovery. However, the use of MZT resulted in faster induction and a more reliable plane of anesthesia that was reversible with atipamezole and safer than other previously used intramuscular agents. Physiological parameters including heart rate, respiratory rate, temperature, pulse oximeter saturation, and end-tidal carbon dioxide were monitored.     

Use of medetomidine-ketamine and atipamezole for reversible immobilization of free-ranging hog deer (Axis porcinus) captured in drive nets

A combination of 0.05 mg/kg medetomidine and 1.5 mg/kg ketamine was used to immobilize nine adult free-ranging hog deer (Axis porcinus) captured in drive nets in the Royal Bardia National Park, Nepal, 22-23 February 2000. The drugs were administered intramuscularly from separate syringes and the mean time (+/-SD) to complete immobilization was 4.6+/-1.0 min. Muscle relaxation was good and no major clinical side effects were seen. Mean values for physiologic parameters, recorded at 10-12 and 18-20 min after drug administration, were 40.6+/-0.5 and 41.1+/-0.6 C, 87+/-5 and 84+/-4%, 107+/-16 and 113+/-16 beats/ min, and 46+/-9 and 40+/-8 breaths/min for rectal temperature, SpO2, pulse rate, and respiratory rate, respectively. All animals received 0.25 mg/ kg atipamezole intramuscularly 20-22 min after administration of medetomidine-ketamine and the mean time to coordinated running was 4.8+/-0.8 min. All animals survived for at least 5 mo post-capture. To reduce stress and to facilitate handling, medetomidine-ketamine and atipamezole are recommended for reversible immobilization of free-ranging hog deer captured in drive nets.     

Immobilization of free-ranging European mink (Mustela lutreola) an polecat (Mustela putorius) with medetomidine-ketamine and reversal by atipamezole

From March 1996 to August 1999, 24 free-ranging European mink (Mustela lutreola) and 25 free-ranging polecats (Mustela putorius) were immobilized for clinical procedures and to place radio transmitters. Data were recorded during 14 and 12 trials, respectively. Animals received intramuscularly 10 mg/kg ketamine (KET) combined with 0.20 mg/kg medetomidine (MED), antagonized by 1.00 mg/kg atipamezole (ATI). Anesthesia times were similar between species. Induction was smooth and rapid (0.7-3.9 min); the degree of anesthesia and muscle relaxation was satisfactory in most animals. Two individuals showed signs of spontaneous recovery before injection of ATI. In other individuals, ATI was injected 28.1-54.0 min after the MED-KET injection and rapidly reversed the effects of the MED. Rectal temperature and heart and respiratory rates decreased significantly 5-25 min post MED-KET injection in both species. Rectal temperature successfully remained stable by placing animals on a warmed plastic table (37 C) during anesthesia. According to these results, this anesthetic protocol produces a safe and rapid immobilization in free-ranging European mink and polecats and is recommended for surgical procedures such as radio transmitter implantation. However caution is required as hypothermia can be severe. Body temperature must be monitored and means provided to maintain stability.     

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.     

Effectiveness of antagonists for tiletamine-zolazepam/xylazine immobilization in female white-tailed deer

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 alpha(2) antagonist treatment to reverse xylazine-induced sedation (seven does per group). All deer were given 220 mg of TZ (4.5+/-0.4 mg/kg) and 110 mg of X (2.2+/-0.2 mg/kg) intramuscularly (IM). Antagonist treatments were either 200 mg of tolazoline (4.0+/-0.4 mg/kg), 11 mg of atipamezole (0.23+/-0.02 mg/kg), or 15 mg of yohimbine (0.30+/-0.02 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 alpha(2) antagonist treatments (P=0.02). Times were longer for yohimbine (62.3+/-42.7 min) than for either atipamezole (24.3+/-17.1 min) or tolazoline (21.3+/-14.3 min). Mean times from antagonist injection until standing were not different (P=0.15) among yohimbine (112.0+/-56.4 min), atipamezole (89.7+/-62.8 min), or tolazoline (52.6+/-37.2 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.     

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.     

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.     

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)     

Immobilization of free-ranging nine-banded and great long-nosed armadillos with three anesthetic combinations

Nine-banded (n = 47) and great (n = 31) long-nosed armadillos (Dasypus novemcinctus and Dasypus kappleri) were immobilized for clinical examination and collection of biological samples as part of a wildlife rescue during the filling of a hydroelectric dam (Petit Saut, French Guiana) from May 1994 to April 1995. Three intramuscular (i.m.) anesthetic combinations were evaluated: (1) tiletamine/zolazepam (T/Z) at a dose of 8.5 mg/kg in 12 nine-banded long-nosed armadillos (NBA) and 10 great long-nosed armadillos (GLA), (2) ketamine at 40 mg/kg combined with xylazine at 1.0 mg/kg (K/X) in 18 NBA and nine GLA, and (3) ketamine at 7.5 mg/kg combined with medetomidine at 75 microng/kg (K/M) in 17 NBA and 12 GLA, antagonized by 375 microg/kg atipamezole. Induction was smooth, ranged from mean +/- SD = 2.8+/-0.6 to 4.3+/-1.8 min, and did not differ significantly between protocols, species, or sex. In NBA, immobilization time ranged from 43.8+/-27.8 to 66.5+/-40.0 min and did not differ between protocols or sex. Muscle relaxation was judged to be better with K/X and K/M versus T/Z. In GLA, the response to the anesthetic protocols was more variable and immobilization time ranged from 30.4+/-6.2 to 98.4+/-33.7 min. The main difference was observed in GLA females receiving the T/Z combination, in which immobilization time was significantly longer versus males, but also versus GLA K/M group, and versus NBA T/Z group. Effects on body temperature, heart rate and respiratory rate were limited. Thirty six to 50% of the individuals showed hypoxemia (SpO2 < 85%) throughout anesthesia and values <80% also were recorded but the hypoxemia was not associated with clinical signs. With T/Z and K/X, recovery was irregular and prolonged up to 2 to 3 hr in some individuals. In K/M groups, first standing was observed 1.0 to 16.4 min after i.m. atipamezole injection without adverse effects. Finally, the three anesthetic combinations used in this study were effective and safe agents for 30 to 40 min immobilizations including minor surgery procedures. The ability to antagonize the medetomidine-induced sedation with atipamezole significantly reduces the recovery time, making the K/M combination preferable, especially in field conditions.     

Anesthesia of boma-captured Lichtenstein's hartebeest (Sigmoceros lichtensteinii) with a combination of thiafentanil,medetomidine, and ketamine

A dose range was determined for anesthesia of recently boma-captured Lichtenstein's hartebeest (Sigmoceros lichtensteinii) (n = 13) with the synthetic opiate thiafentanil (THIA) (formerly called A3080) combined with medetomidine (MED) and ketamine (KET) in the Kasungu National Park, Malawi on 4 to 5 September 1999. The dose range of 11-29 micrograms/kg THIA (mean +/- SD = 21 +/- 4 micrograms/kg) combined with 5-10 mg/kg MED (8 +/- 1 micrograms/kg) plus 0.7-1.4 mg/kg KET (1.1 +/- 0.2 mg/kg) was found to be safe and effective for the field conditions associated with this study. The anesthesia produced by this drug combination was very predictable and characterized by a short induction time (3:34 +/- 1:20 min:sec), good muscle relaxation, and acceptable physiologic parameters for anesthesia periods ranging from 22:30-35:00 min:sec (31:14 +/- 2:50). Within the range of doses used in this study, times to onset of initial effects and recumbency were not dependent on THAI, MED, or KET doses. Anesthesia was rapidly and completely reversed by intravenous injections of naltrexone at 30 times the THAI dosage (0.69 +/- 0.19 mg/kg) and atipamezole at about four times the MED dosage (38 +/- 14 micrograms/kg). There was no residual effect from ketamine noted following reversal of THIA and MED and no mortality or morbidity was associated with this anesthetic regimen.     

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.     

Sufentanil and medetomidine anaesthesia in the rat and its reversal with atipamezole and butorphanol

Injectable anaesthetics are widely used to anaesthetize rats, but recovery times are often prolonged. Reversible anaesthetic regimens have the advantage that animals may be recovered quickly, thus reducing the incidence of postoperative complications such as hypothermia, and also providing a means of treating inadvertent anaesthetic overdose. This study assessed and compared the characteristics of anaesthesia induced with combinations of sufentanil and medetomidine administered as a single subcutaneous or intraperitoneal dose, and reversal with butorphanol and atipamezole. Combinations of sufentanil/medetomidine at 40 microg/150 microg and 50 microg/150 microg/kg administered subcutaneously, and 80 microg/300 microg/kg by intraperitoneal injection were found to produce surgical anaesthesia for 101+/-49, 124+/-45 and 76+/-23 min (means +/- SD) respectively. All three combinations produced marked respiratory depression 30 min after injection (< 50% of resting respiratory rate). Oxygen saturation, measured by pulse oximetry, was < 50% in all groups 30 min following drug administration. Subcutaneous administration is recommended since it resulted in a more reliable and more rapid induction of anaesthesia than intraperitoneal administration. The administration of butorphanol and atipamezole (0.2/0.5 mg/kg s.c.) resulted in a rapid (< 7 min) reversal of anaesthesia and an associated respiratory depression. The induction of anaesthesia with sufentanil/medetomidine and its reversal with a combination of atipamezole and butorphanol is an effective technique for anaesthetizing rats. However, due to the marked respiratory depression and the resulting hypoxia, we recommend that this regimen should only be used in animals which are free from respiratory disease and that oxygen should be provided during anaesthesia.     

Field immobilization of feral 'Judas' donkeys (Equus asinus) by remote injection of medetomidine and ketamine and antagonism with atipamezole

The Judas technique is a method used for landscape control of feral donkeys (Equus asinus) in northern Australia. Central to the success of any Judas program is the safe, efficient, and humane attachment of the telemetry device. For feral donkeys, this involves the use of field immobilization. We examine the replacement of the current chemical capture agent, succinylcholine, with contemporary immobilization agents to achieve positive animal welfare outcomes. A combination of medetomidine and ketamine delivered by remote injection from a helicopter was used to capture 14 free-ranging feral donkeys for the fitting of telemetry collars in Western Australia in November 2010. Dose rates of 0.14 mg/kg medetomidine and 4.1 mg/kg ketamine were appropriate to immobilize animals in 9 min (± SD = 3). Mean recovery time (total time in recumbency) was 21 min (± 14). All animals recovered uneventfully after being administered atipamezole, a specific antagonist of medetomidine, intramuscularly at 0.35 mg/kg. Physiologic parameters were recorded during recumbency, with environment-related hyperthermia being the only abnormality recognized. No significant complications were encountered, and this drug combination represents an efficient approach to capturing wild donkeys. This new method allows a rapid, safe, cost-effective approach to the immobilization of feral donkeys for use as Judas animals. This drug combination will replace the relatively inhumane succinylcholine for the field immobilization of feral donkeys.     

Anesthesia of polar bears using xylazine-zolazepam-tiletamine or zolazepam-tiletamine

Immobilization features and physiologic effects of combinations of xylazine-zolazepam-tiletamine (XZT) and zolazepam-tiletamine (ZT or Telazol) were compared in nine captive and 17 free-ranging polar bears (Ursus maritimus) between 1998 and 2001. Although induction time was similar between drugs, induction dosage and volume were less with XZT. Induction of immobilization with XZT was predictable and smooth, muscle relaxation was good, and all bears remained completely immobilized and unresponsive to stimuli throughout a 1 hr handling period. The combination XZT was safely tolerated at two to three times the recommended dosage of 5 mg/kg (i.e., xylazine at 2 mg/kg + Telazol at 3 mg/kg). Bears immobilized with XZT had slower pulse rates, higher mean arterial pressures, and lower arterial oxygen tensions than bears immobilized with ZT. Rectal temperature increased slowly over time (approximately 0.5 C per hr) following immobilization with XZT. Based on response to a painful stimulus (compression of a claw bed), XZT was a more effective analgesic than ZT. Although the immobilization effects of XZT could not be reversed with the alpha 2-antagonist drug tolazoline, they were reversed with yohimbine or atipamezole. However, the time to complete reversal of effects (i.e., standing and ambulatory) was highly variable among bears.     

Comparative immobilization of wild felids in Thailand

We immobilized individuals of four free-ranging felid species, leopard cat (Prionailurus bengalensis), clouded leopard (Neofelis nebulosa), Asiatic golden cat (Catopuma temminckii), and marbled cat (Pardofelis marmorata) with ketamine hydrochloride and xylazine hydrochloride (KH-XH) and with tiletamine hydrochloride and zolazepam hydrochloride (TH-ZH) between March 1998 and July 2002. Mean (+/-SD) dose of KH and XH was 26.51+/-5.71 mg/kg and 1.89+/-0.43 mg/kg, respectively (n=25), and mean dose of TH-ZH was 11.61+/-3.39 mg/kg (n=28). Dose was significantly correlated with induction time (P<0.001) and duration of anesthesia (P<0.05), but not with recovery time. There were significant differences between the drug combinations in time to induction (P<0.03) and time to anesthesia (P<0.01); recovery times were not significantly different. We conclude that immobilization of these felids with TH-ZH and KH-XH is effective and safe, but TH-ZH is preferred because of the smaller volume of drug necessary for sedation, faster time to induction, and absence of prolonged muscle rigidity during anesthesia.     

Immobilization of Chacoan peccaries (Catagonus wagneri) using medetomidine, Telazol, and ketamine

A combination of medetomidine, Telazol, and ketamine hydrochloride was used to immobilize captive Chacoan peccaries (Catagonus wagneri) for translocation within Paraguay during August-October 2002. Animals were darted in enclosed areas of varying size. The average dose used was 32.5+/-7.2 microg/kg of medetomidine, 0.63+/-0.2 mg/kg of Telazol, and 3.9+/-0.65 mg/kg of ketamine. First effects were noted at 4.3+/-2.1 min, and ability to handle the animals was achieved by 12.6+/-3.7 min. Heart and respiratory rates declined and oxygen saturation increased during anesthesia. Muscle relaxation was good. Atipamezole was used to antagonize the medetomidine, although recoveries were still slow. This drug combination provided adequate immobilization of Chacoan peccaries; however, this protocol would not be considered to be reversible, and confinement during recovery is recommended.     

Field Sedation of Coyotes,Red Foxes,and Raccoons With Medetomidine and Atipamezole

Abstract: We chemically restrained free-ranging coyotes (Canis latrans), red foxes (Vulpes vulpes), and raccoons (Procyon lotor) using medetomidine antagonized by atipamezole. All coyotes and 80% of red foxes were sedated with mean ± standard deviation doses of 0.12 ± 0.02 mg/kg and 0.14 ± 0.02 mg/kg medetomidine, respectively. Seventy-seven percent of raccoons were sedated with 0.21 ± 0.05 mg/kg medetomidine. In all species we observed occasional movement, muscle rigidity, and partial-arousal during sedation. Animals were alert within 4.3–8.6 ± 3.5–8.4 min following atipamezole at 0.4 mg/kg. Medetomidine and atipamezole provided safe handling in most animals and rapid recovery without use of a controlled substance. At these doses, biologists in the field should be prepared to administer a supplementary dose of medetomidine to some animals depending on ambient conditions and the objectives of the restraint event.     

Anaesthesia of free-ranging Northern chamois (<Emphasis Type="Italic">Rupicapra rupicapra</Emphasis>) with xylazine/ketamine and reversal with atipamezole

One-hundred and fifty-five free-ranging Northern chamois (Rupicapra rupicapra) were anaesthetised in the course of a restocking programme using xylazine plus ketamine. Mean ± SD dosages for xylazine and ketamine were 1.9 ± 0.5 and 2.2 ± 0.7 mg/kg, respectively. In 57 chamois, sedation was reversed using 0.3 ± 0.1 mg/kg atipamezole. Although all the anaesthetic dosages tested immobilised free-ranging Northern chamois, shorter induction times (4.8 ± 2.6 min), deeper sedation with no reaction to handling in >90% of the animals and quick reversal (4.0 ± 2.7 min) were obtained using 2.5 mg/kg xylazine plus 3.0 mg/kg ketamine reversed with 0.25 mg/kg atipamezole. Under the conditions of this study, suggested standard doses are 63 mg/animal xylazine plus 76 mg/animal ketamine reversed by 6.3 mg/animal atipamezole. This anaesthetic protocol improves the results from the previous study of Dematteis et al. (Vet Rec 163:184–189, 2008) using xylazine alone.     

Reversible immobilization of eurasian otters with a combination of ketamine and medetomidine

The efficacy and safety of the combination of medetomidine and ketamine was examined in order to establish an adequate chemical immobilization protocol in the Eurasian otter (Lutra lutra) for use during translocation projects in Spain. Thirty-eight Eurasian otters ranging in body mass from 3 to 8.7 kg (mean 5.3 kg) were successfully anesthetized on 82 occasions. The dosage of ketamine was 5.1+/-0.8 (3.4-6.6) mg/kg (mean +/- SD; range) combined with medetomidine at a dosage of 51+/-8 Rg/kg (34-66 microg/kg). In most cases anaesthetic effect occurred within 3 min and the mean induction time was 5.5+/-3.2 min. The mean pulse rate was 95 beats/min. The mean respiratory rate was 32 respirations/min while the relative oxyhemoglobin saturation was 93%. According to these results, this anesthetic protocol is considered safe and can be recommended in wild caught Eurasian otters for immobilization during translocation projects. It is safe, rapid and can be reversed when needed with atipamezole. However caution is required as heart depression resulting in bradychardia may occur.