BUTORPHANOL, AZAPERONE, AND MEDETOMIDINE ANESTHESIA IN FREE-RANGING EASTERN MOOSE (ALCES AMERICANUS).

Fifty-three free-ranging moose (Alces americanus) cows were darted from a helicopter with 3-4 ml of a premix combination of butorphanol (27.3 mg/ml), azaperone (9.1 mg/ml), and medetomidine (10.9 mg/ml; BAM), equivalent to estimated dosages of: butorphanol 0.26 ± 0.08 (mean ± SD) mg/kg, azaperone 0.09 ± 0.03 mg/kg, and medetomidine 0.11 ± 0.03 mg/kg. After a mean chase time (from sighting to darting) of 6.1 ± 5.5 min, the mean induction time (from darting to recumbency) was 8.3 ± 2.6 min. This combination provided a safe and reliable sedation for minor procedures that lasted 30-60 min. Heart rate (50.4 ± 7.0 beats/min), respiratory rate (21.3 ± 11.1 breaths/minute), ETCO2 via nasal canula (43.2 ± 7.0 mmHg), and rectal temperature (38.5°C ± 0.7°C) mostly remained at expected values for wild cervid and bovid species anesthetized with this drug combination. SpO2 (90.0% ± 3.7%) was suggestive of moderate hypoxemia despite intranasal oxygen supplementation (1 L per 100 kg/min). The recovery time to standing was 6.7 ± 3.8 min after reversal with IM naltrexone (3 mg/mg butorphanol) and atipamezole (5 mg/mg medetomidine). Despite a larger volume to inject, this protocol offers an alternative to highly potent opioids, and should be considered for practical or staff safety reasons. On the basis of the results of this study, the use of 4 ml of BAM is considered a safe and effective protocol for immobilization of cow moose under comparable settings.

EVALUATING THE USE OF A BUTORPHANOL-AZAPERONE-MEDETOMIDINE FIXED-DOSE COMBINATION FOR STANDING SEDATION IN AFRICAN ELEPHANTS (LOXODONTA AFRICANA).

This study investigated the use of a fixed-dose combination of 30 mg/ml butorphanol, 12 mg/ml azaperone, and 12 mg/ml medetomidine for the standing sedation of captive African elephants (Loxodonta africana). In total, seven females (mean age 19.6 yr; range 6-31 yr) and six males (mean age 33.5 yr; range 9-35 yr) were sedated. The estimated dose was 0.0005 ± 0.0001 ml/kg and 0.006 ± 0.001 ml/cm shoulder height, which resulted in a dose of 0.016 ± 0.002 mg/kg or 0.19 ± 0.04 mg/cm shoulder height butorphanol, 0.006 ± 0.0008 mg/ kg or 0.076 ± 0.015 mg/cm shoulder height azaperone, and 0.006 ± 0.0008 mg/kg or 0.076 ± 0.015 mg/cm medetomidine. First signs of sedation were observed within 3-10 min (mean 6 ± 2 min) after darting, and monitoring of the animals started on average at 24 ± 9 min after darting. No bradycardia was observed in any of the elephants (mean heart rate 40.0 ± 6.55 beats/min), although all the animals were mildly hypotensive (mean blood pressure 118.5/86 [94.5]). Rectal temperatures fell within acceptable ranges, and respiratory parameters were stable in all the animals throughout sedation and fell within the standard ranges reported for conscious, standing elephants. Only one elephant had clinically significant hypoxemia characterized by a partial pressure of oxygen (PaO2) < 60 mm Hg. This elephant was also hypercapnic (PaCO2 > 50 mm Hg), although pH and peripheral capillary oxygen saturation fell within acceptable ranges. None of the elephants reacted to moderately painful stimuli while sedated. The combination was reversed with intramuscular injections of naltrexone (1 mg for every 1 mg butorphanol) and atipamezole (5 mg for every 1 mg medetomidine). Recovery was smooth and calm in all the animals. Time from injection of the reversals until the first signs of recovery was 4.6 ± 2.01 min (range 1-8 min).

EVALUATION OF TWO MEDETOMIDINE-AZAPERONE-ALFAXALONE COMBINATIONS IN CAPTIVE ROCKY MOUNTAIN ELK (CERVUS ELAPHUS NELSONI).

Alfaxalone has been successfully used intramuscularly (im) combined with medetomidine and azaperone for immobilization of small ungulates. An experimental 40 mg/ml alfaxalone solution (RD0387) was recently formulated for reduced injection volume. The objective of this study was to assess the efficacy and cardiopulmonary effects of high-concentration alfaxalone combined with medetomidine and azaperone for the intramuscular immobilization of captive Rocky Mountain elk (Cervus elaphus nelsoni). Seven adult female elk were used in a crossover design in which they were administered alfaxalone 1 mg/kg, medetomidine 0.05 mg/kg, and azaperone 0.1 mg/kg or alfaxalone 0.5 mg/kg, medetomidine 0.1 mg/kg, and azaperone 0.1 mg/kg im approximately 3 wk apart. Drugs were delivered to each elk in a chute by hand injection. Once recumbent, elk were placed in sternal recumbency for a period of 30 min, during which time level of sedation, response to minor procedures, heart rate, respiratory rate, rectal temperature, oxygen saturation, and direct arterial blood pressures were recorded every 5 min. Arterial blood gases were performed every 15 min. At 30 min, elk were administered atipamezole 0.25 or 0.5 mg/kg im and recovery quality and times were recorded. Statistical comparisons were made by t test, Wilcoxon signed rank test, and repeated measures analysis (significance level P < 0.05). Both drug combinations provided effective immobilization for 30 min, with induction and recovery time and quality similar to other medetomidine-based combinations used in elk. Cardiopulmonary effects included bradycardia, hypertension, and hypoxemia that resolved with oxygen supplementation. The average injection volume in the low-dose alfaxalone combination was approximately 5 ml. These combinations provided deep sedation and the ability to perform minor procedures in captive elk, with acceptable cardiopulmonary parameters as long as supplemental oxygen was provided.

EVALUATION OF TWO ANESTHETIC COMBINATIONS IN LOWLAND NYALA (TRAGELAPHUS ANGASII).

Fourteen lowland nyala (Tragelaphus angasii) in managed care were successfully anesthetized for a total of 17 anesthetic events using either a combination of butorphanol (0.75 ± 0.15 mg/kg), azaperone (0.25 ± 0.05 mg/kg), and medetomidine (0.30 ± 0.06 mg/kg) (BAM) or medetomidine (0.17 ± 0.01 mg/kg), azaperone (0.22 ± 0.02 mg/kg), and alfaxalone (0.52 ± 0.08 mg/kg) (MAA) delivered intramuscularly via dart. Mean time to initial effect, sternal recumbency, lateral recumbency, handling, and intubation were recorded. The nyala were maintained in sternal recumbency with supplemental oxygenation until 60 min after initial injection. Cardiopulmonary effects were recorded every 5 min after handling until reversal. Arterial blood samples were collected every 15 min for analysis. Level of sedation and quality of recovery were scored. Anesthesia was antagonized with atipamezole (at 5 mg per mg of medetomidine) for both protocols and naltrexone (at 2 mg per mg of butorphanol) for the BAM protocol delivered intramuscularly via hand injection. Mean time to extubation, head control, and standing post reversal were recorded. No hyperthermia, acidemia, apnea, or tachycardia occurred; however, animals did display hypoxemia. Two animals in the BAM cohort required supplementation to facilitate handling. These drug combinations provided satisfactory levels of sedation in most cases for safe handling and minor procedures in lowland nyala under managed care.

Tissue Residue Levels of the Tranquilizer Combination of Butorphanol, Azaperone, and Medetomidine, and the Antagonists, Naltrexone, Atipamezole, and Tolazoline, in Black Bears (Ursus americanus) Postimmobilization.

The tranquilizer combination of butorphanol, azaperone, and medetomidine (BAM) has shown good efficacy for immobilization of wildlife, including black bears (Ursus americanus). BAM is antagonized with a combination of naltrexone and atipamezole. We immobilized 19 adult captive wild caught black bears and, except for three bears that were euthanized immediately, bears were recovered with naltrexone and atipamezole. Tissue residues (≥0.01 ppm) for the tranquilizers butorphanol, azaperone, and medetomidine were detected in liver and muscle of all three bears euthanized on day 0 postinjection (PI). Azaperone was not detected after 1 d PI. Residue for medetomidine was detected in two bears: in the liver 3 d PI and in the kidney 6 d PI. Butorphanol was reported in three bears: in fat 5 d PI, in kidney 6 d PI, and, surprisingly, in kidney, muscle, and fat 7 d PI. No tissue residues were detected in the three bears euthanized at 8 d PI. Tissue residues for the antagonists, naltrexone and atipamezole, were detected in bears euthanized 2 and 6 d PI, but not in tissues from animals euthanized at 7 or 8 d PI.

EVALUATION OF THE QUALITY OF IMMOBILIZATION AND CARDIORESPIRATORY EFFECTS OF ETORPHINE-MEDETOMIDINE-AZAPERONE COMBINATION IN PLAINS ZEBRAS (EQUUS QUAGGA): A PILOT STUDY.

Five free-ranging male (subadults, n = 3; adults, n = 2) plains zebras (Equus quagga) were immobilized using a combination of etorphine (0.017 mg/kg), medetomidine (0.017 mg/kg), and azaperone (0.24 mg/kg) by means of a blank cartridge-fired projector. Time to recumbency was recorded and a descriptive score used to assess the quality of immobilization, manipulation, maintenance, and recovery. Physiological parameters were recorded at 5-min intervals for 20 min. At the end of the procedure, naltrexone (0.23 mg/kg) was administered intramuscularly and time to standing documented. The combination evaluated in this study allowed for successful immobilization and safe recovery of all animals, including during the subsequent 15 days. Despite the good outcome in this pilot study, as a result of the periodic apneic events and hypercapnia documented in the zebras, the authors suggest that physiological parameters be thoroughly monitored when using this protocol. Further studies are needed to improve upon chemical immobilization protocols in free-ranging plains zebras.

Compared to etorphine-azaperone, the ketamine-butorphanol-medetomidine combination is also effective at immobilizing zebra (Equus zebra).

OBJECTIVE: To compare immobilization efficacy of a nonpotent opioid drug combination, ketamine-butorphanol-medetomidine (KBM) to the preferred etorphine-azaperone (EA) combination in zebras. STUDY DESIGN: Randomized crossover trial. ANIMALS: A group of ten adult zebra (six females and four male). METHODS: KBM and EA were administered once to the zebras in random order by dart, 3 weeks apart. Once a zebra was recumbent and instrumented, physiological parameters were measured and recorded at 5-minute intervals until 20 minutes. Antagonist drugs were administered at 25 minutes. KBM was antagonised using atipamezole (7.5 mg mg-1 medetomidine dose) and naltrexone (2 mg mg-1 butorphanol dose). EA was antagonized using naltrexone (20 mg mg-1 etorphine dose). Induction and recovery (following antagonist administration) times were recorded. Physiological parameters, including invasive blood pressure and blood gas analysis, were compared between combinations using a general linear mixed model. Data are reported as mean ± standard deviation or median (interquartile range). RESULTS: The doses of KBM and EA administered were 3.30 ± 0.18, 0.40 ± 0.02 and 0.16 ± 0.01 mg kg-1; and 0.02 ± 0.001 and 0.20 ± 0.01 mg kg-1, respectively. KBM and EA induction times were 420 (282-564) and 240 (204-294) seconds, respectively (p = 0.03). Zebras remained recumbent throughout the study procedures. Systolic blood pressure (226 ± 42 and 167 ± 42 mmHg) and oxygen partial pressure (64 ± 12 and 47 ± 13 mmHg) were higher for KBM compared to EA (p < 0.01). Recovery time, after administering antagonists, was 92 (34-1337) and 26 (22-32) seconds for KBM and EA, respectively (p = 0.03). CONCLUSIONS AND CLINICAL RELEVANCE: Compared to EA, KBM also immobilized zebras effectively. Systemic hypertension and moderate hypoxaemia are clinical concerns of KBM and severe hypoxaemia is a concern of EA. This occurrence of hypoxaemia highlights the importance of oxygen administration during immobilization.

Butorphanol-Azaperone-Medetomidine for the Immobilization of Rhesus Macaques (Macaca mulatta).

Maximizing animal wellbeing by minimizing drug-related side effects is a key consideration when choosing pharmaceutical agents for chemical restraint in nonhuman primates. One drug combination that may promote this ideology is butorphanol (27.3 mg/mL), azaperone (9.1 mg/mL), and medetomidine (10.9 mg/mL; BAM). Based on results from a pilot study, 2 doses of BAM (16 and 24 µL/kg IM) were compared in healthy, 3-y-old rhesus macaques. Physiologic parameters and anesthetic quality were assessed and recorded every 5 min. Experimental endpoints were established for hypoxemia (85% or less peripheral oxygen saturation with oxygen supplementation), pulse rate (80 bpm or less for 2 consecutive readings), mean arterial pressure (MAP; 50 mm Hg or less), and hypothermia (97 °F or less); if any endpoint was achieved, medetomidine was reversed by using atipamezole (0.22 mg/kg IM). Both BAM doses resulted in immobilization of all animals with no clinically significant differences between groups. All animals initially exhibited hypoxemia that resolved with oxygen supplementation. Regardless of dose, most macaques (71%) reached established experimental endpoints for bradycardia (62 to 80 bpm) or hypotension (44 to 50 mm Hg MAP). Given the results of this study, our recommendation regarding the use of 16- or 24-µL/kg BAM for immobilizing rhesus macaques is dependent on caution regarding cardiopulmonary parameters and the provision of supplemental oxygen.

Immobilization of American Beaver (Castor canadensis) with Nalbuphine, Medetomidine, and Azaperone.

Thirty-two American beavers (Castor canadensis) were immobilized with a mixture of nalbuphine, medetomidine, and azaperone (NalMedA) for tail transmitter placement and health assessments prior to translocation. Inductions and reversals were very smooth, but regardless of the dose administered, which ranged from 0.02 to 0.06 mL/kg, many beavers reacted to mild stimuli such as being lifted out of the cage, drawing blood from the tail, expressing anal glands for sex determination, and turning on isoflurane to deepen anesthesia before placement of tail transmitters. On a scale from 1 to 5, a sedation score of 4 was achieved in 8/32 beavers and a sedation score of 5 in 1/32 of beavers given a mean (SD) dosage of 0.04 (0.01) mL/kg NalMedA, which equated to a mean of 1.09 (0.21) mg/kg nalbuphine, 0.43 (0.09) mg/kg medetomidine, and 0.36 (0.07) mg/kg azaperone. All other animals achieved lower sedation scores. Supplementary isoflurane was needed to deepen anesthesia before tail transmitter placement. Although Nal-MedA appeared to be safe for use in American beavers, the level of sedation achieved was quite variable. Supplementary oxygen is recommended to reduce hypoxemia.

Chemical capture of wild swamp buffalo (Bubalus bubalis) in tropical northern Australia using thiafentanil, etorphine and azaperone combinations.

BACKGROUND: Studying wild animals in situ is fundamental to collecting baseline information, but generally they need to be immobilised for examination, sampling, marking and/or equipping with tracking apparatus. Capturing wild animals is inherently risky and there is a need for immobilisation methods that are safe for both the animals and researchers. METHODS: A total of 16 free-ranging swamp buffalo (Bubalus bubalis) were chemically captured by dart for the application of satellite tracking collars in tropical northern Australia; 7 animals were anesthetised with a thiafentanil-etorphine-azaperone (TEA) combination and 9 animals with a thiafentanil-azaperone (TA) combination. Anaesthesia was reversed with intravenous naltrexone. Mean dosages of etorphine and thiafentanil for animals in the TEA group were 0.01 mg/kg of each drug and mean dosage of thiafentanil for animals in the TA group was 0.02 mg/kg. Total dose per animal of azaperone and naltrexone was 80 mg and 150 mg, respectively. Anaesthetic monitoring was by physical observation of physiological variables, pulse oximetry and capnography. Blood laboratory parameters including creatine kinase (CK), aspartate transaminase (AST), serum bicarbonate and anion gap were measured. RESULTS: All subject animals recovered well from anaesthesia despite the occurrence of subclinical acidosis in some patients. There was no significant difference between the treatment groups. Conversely, chase time had an adverse effect on body temperature, irrespective of the anaesthetic combination used. CONCLUSIONS: Thiafentanil and azaperone, with or without etorphine, delivered rapid safe, effective, reversible field anaesthesia in healthy swamp buffalo.

EVALUATION OF CHEMICAL IMMOBILIZATION IN CAPTIVE BLACK BEARS ( URSUS AMERICANUS) RECEIVING A COMBINATION OF NALBUPHINE, MEDETOMIDINE, AND AZAPERONE.

To assess potential seasonal differences in responses to immobilization, we sedated eight orphaned yearling black bears ( Ursus americanus) being held for rehabilitation at a wildlife facility in Colorado, US, using a premixed combination of nalbuphine (40 mg/mL), azaperone (10 mg/mL), and medetomidine (10 mg/mL; NalMed-A) in October (autumn) prior to hibernation and again after emergence in May (spring) prior to their release. We dosed all bears at 1 mL NalMed-A per estimated 45 kg body mass (1 mL NalMed-A/45 kg), delivered by intramuscular injection using a pole syringe, to facilitate routine examination and ear tagging. Arterial blood gases were measured to assess oxygenation and acid-base status of bears both pre and post oxygen supplementation. The mean (SE) dose calculated post hoc was 0.9 (0.04) mg nalbuphine/kg, 0.2 (0.01) mg azaperone/kg, and 0.2 (0.01) mg medetomidine/kg. The mean induction time was 8 (1) min for six of the bears in October and 6 (1) min for eight bears in May. The NalMed-A combination provided good sedation in captive yearling black bears in autumn and spring and was effectively antagonized with a combination of naltrexone and atipamezole. Mild hypoxemia (PaO2: 53.5-54.4 mmHg) was the most significant side effect and was corrected (PaO2: 68.4-150.1 mmHg) with supplemental oxygen administered at 2-5 L/min for 5 min (point of sampling).

Evaluation of butorphanol-azaperone-medetomidine in captive cheetah (Acinonyx jubatus) immobilization.

OBJECTIVE: The butorphanol-azaperone-medetomidine fixed-dose combination (BAM, respectively, 30-12-12 mg mL-1) with subsequent antagonism by naltrexone-atipamezole was evaluated for reversible immobilization of captive cheetahs (Acinonyx jubatus). STUDY DESIGN: Prospective, clinical trial. ANIMALS: Twelve cheetahs (six males and six females, weighing 37-57 kg) housed in enclosures, were immobilized at Hoedspruit Endangered Species Centre in the Republic of South Africa. METHODS: BAM volume dose rate was 0.009-0.014 mL kg-1 (mean ± standard deviation 0.010 ± 0.001 mL kg-1). Total dose in all animals was 0.5 mL. The actual doses were as follows: butorphanol (0.29 ± 0.04 mg kg-1), azaperone (0.12 ± 0.01 mg kg-1) and medetomidine (0.12 ± 0.01 mg kg-1). Physiologic variables and quality of immobilization were recorded every 5 minutes beginning at 15-20 minutes after darting. Arterial blood samples were collected three times at 20, 30 and 40 minutes after darting from all animals for analysis of blood oxygenation and acid-base status. RESULTS: The inductions were calm and smooth and mean induction time was 4.0 ± 1.1 minutes. Heart rate (50 ± 9 beats minute-1) and respiratory frequency (20 ± 3 breaths minute-1) were stable throughout immobilization. The recovery time after reversing with naltrexone and atipamezole was 9.1 ± 3.6 minutes. CONCLUSIONS: and clinical relevance BAM proved to be a reliable and cardiovascular stable drug combination for immobilization of cheetahs.

COMPARISON OF THE EFFICACY AND SAFETY OF MEDETOMIDINE-KETAMINE VERSUS MEDETOMIDINE-AZAPERONE-ALFAXALONE COMBINATION IN FREE-RANGING ROCKY MOUNTAIN BIGHORN SHEEP ( OVIS CANADENSIS).

Chemical immobilization is a key aspect of wildlife management. To minimize dose-dependent adverse effects, immobilization protocols often include two or more synergistic agents, which allows for reductions in individual drug dosages. Free-ranging bighorn sheep ( Ovis canadensis) in Canada ( n = 74) were remotely injected with a combination of medetomidine (0.16 ± 0.04 mg/kg) and ketamine (4.0 ± 1.4 mg/kg) (MK), or combination of medetomidine (0.14 ± 0.06 mg/kg), azaperone (0.21 ± 0.11 mg/kg), and alfaxalone (0.45 ± 0.21 mg/kg) (MAA). Once recumbency was achieved, arterial blood samples were collected and immediately analyzed for blood gas and acid-base status. Rectal temperature, heart rate, and respiratory rate were recorded upon recumbency and throughout anesthesia at 5-15 min intervals. At conclusion of the procedures, medetomidine was reversed by intramuscular atipamezole at five times the medetomidine dose. Induction times (mean ± standard deviation) of animals that became immobilized with one dart (8.7 ± 3.2 min, 7.3 ± 3.9 min) and recovery times of all animals (3.4 ± 1.5 min, 3.9 ± 1.6 min) were not significantly different between MK and MAA groups, respectively. Both MK and MAA groups experienced severe hypoxemia (PaO2 42 ± 9 mmHg, 40 ± 10 mmHg, respectively). PaCO2 was significantly higher ( P = 0.0248) in the MK group (median 54 mmHg) than the MAA group (median 48 mmHg) with a trend towards lower pH (7.40 vs 7.42, respectively, P = 0.07). Initially, MK animals had higher heart rates than MAA animals (median 49 vs 40 beats/min), which decreased over time. In bighorn sheep, both MK and MAA produced reliable, reversible immobilization with smooth inductions and recoveries. However, less respiratory depression was seen with MAA than MK.

[Evaluation of a field-suitable injection anesthesia protocol for the castration of 8 to 14 days old piglets]. / Ermittlung eines feldtauglichen Injektionsanästhesieprotokolls zur Kastration von 8 bis 14-tägigen Ferkeln.

INTRODUCTION: The aim of this study was to find an intramuscularly (IM) injectable anaesthetic combination for 8 to 14-days old piglets, that guarantees a calm induction and sufficient quality of anaesthesia without excitations with a maximum of two hours long lasting recovery. In preliminary dose finding trials, different combinations of -ketamine, azaperone and romifidine were compared. A constant dose of 0.2 mg/kg of butorphanol was added to each combination and all piglets received 0.4 mg/kg meloxicam. Subsequently a dosage algorithm for the main trial was developed. In case of insufficient analgesia, lidocaine 2% (0.25 ml) was injected intratesticular. If two piglets showed an insufficient anaesthetic induction phase, depth of anaesthesia or recovery, the next dosage in the algorithm was tried. With the combination of 3 mg/kg azaperone, 0.2 mg/kg romifidine, 15 mg/kg ketamine and 0.2 mg/kg butorphanol the requirement of a smooth anaesthesia induction, sufficient anaesthesia and a recovery without excitation was fulfilled but the recovery lasted more than 120 minutes.

INTRODUCTION: Le but de la présente étude était de mettre au point une combinaison d'anesthésiques injectables par voie intra-musculaire pour les porcelets âgés de 8 à 14 jours qui garantisse une induction calme, une qualité d'anesthésie suffisante (sans mouvement de défense durant l'intervention) et une phase de réveil dépourvue d'excitation et ne durant pas plus de deux heures. Dans le cadre d'un essai préliminaire, on a comparé, afin de définir les doses respectives, des combinaisons de kétamine, d'azapérone et de romifidine. Les résultats ont servi de base pour l'algorithme de dosage de l'essai principal. Les dosages testés étaient les suivants : 1, 2 ou 3 mg/kg d'azapérone, 10 ou 15 mg/kg de kétamine et 0.15 ou 0.2 mg/kg de romifidine. En outre, tous les animaux recevaient du méloxicam (0.4 mg/kg) et du butorphanol (0.2 mg/kg) IM. En cas d'analgésie insuffisante, de la lidocaïne 2% (0.25 ml) était appliquée en intra-testiculaire. Si deux porcelets montraient une phase d'induction, de castration ou de réveil insuffisante, on passait au dosage suivant. Avec la combinaison de 3 mg/kg d'azapérone, 0.2 mg/kg de romifidine, 15 mg/kg de kétamine et de 0.2 mg/kg de butorphanol, les exigences d'une induction calme, d'une qualité d'anesthésie suffisante et d'un réveil dépourvu d'excitation étaient remplies. Toutefois les porcelets dormaient plus de 120 minutes.

Evaluation of butorphanol-azaperone-medetomidine (BAM) in captive blesbok immobilization (Damaliscus pygargus phillipsi).

OBJECTIVE: The fixed-dose combination of butorphanol, azaperone and medetomidine (BAM; 30, 12 and 12 mg mL-1, respectively) with subsequent antagonism by naltrexone-atipamezole was evaluated for reversible immobilization of captive blesbok (Damaliscus pygargus phillipsi). STUDY DESIGN: Prospective, clinical trial. ANIMALS: Sixteen blesbok (four males and twelve females), weighing 52.5-71.0 kg, were immobilized in South Africa. METHODS: The total dose of BAM ranged from 0.5 to 0.7 mL for females and 0.7 to 0.9 mL for males. In seven animals chosen randomly, 8000 units of hyaluronidase was added to the dart. Physiologic variables were recorded every 5 minutes beginning at 10-20 minutes after darting. Arterial blood samples were collected three times at 20, 30 and 40 minutes after darting for analysis of blood acid-base status. RESULTS: The mean administered doses of BAM were as follows: butorphanol (0.34 ± 0.08 mg kg-1), azaperone (0.14 ± 0.03 mg kg-1) and medetomidine (0.14 ± 0.03 mg kg-1). The inductions were calm and smooth. The mean induction time was 9.6 ± 3.2 minutes with just BAM and 5.1 ± 0.8 minutes with BAM and hyaluronidase combination. Heart rate (45 ± 6 beats minute-1) and respiratory frequency (38 ± 4 breaths minute-1) were stable throughout immobilization. The mean arterial blood pressure for all animals was stable but elevated (137 ± 7 mmHg). Rectal temperature slightly increased over time but remained within an acceptable range. The recovery time after administering naltrexone and atipamezole was 4.8 ± 0.7 minutes. CONCLUSION AND CLINICAL RELEVANCE: The BAM combination proved to be reliable and effective in blesbok.

Cardiopulmonary Effects of a Partial Intravenous Anesthesia Technique for Laboratory Swine.

Various anesthetic protocols are used in laboratory swine, each with specific advantages and disadvantages. Partial intravenous anesthetic techniques (PIVA) help minimize dose-dependent cardiopulmonary effects of inhalant drugs. The aim of this study was to determine the cardiopulmonary effects of a PIVA in laboratory swine. In a prospective, nonrandomized clinical study, 8 healthy juvenile Landrace-White pigs were premedicated with azaperone (0.20 ± 0.20 mg/kg IM), dexmedetomidine (0.02 ± 0.002 mg/kg IM), and alfaxalone (2.0 ± 0.20 mg/kg IM), and anesthesia was induced with intravenous alfaxalone. Anesthesia was maintained by using constant-rate infusion of dexmedetomidine (2 µg/kg/h) and alfaxalone (25 µg/kg/min) in combination with isoflurane. After the fraction of expired isoflurane was adjusted to 1.1% to 1.5%, respiratory rate, heart rate, systemic and pulmonary arterial pressure, central venous pressure, cardiac output, bispectral index, systemic vascular resistance, and arterial and mixed venous blood gases were recorded every 10 min for 60 min. Statistical analysis consisted of repeated-measures one-way ANOVA. Significant decreases occurred in heart rate, pulmonary mean arterial pressure, pulmonary diastolic pressure, partial pressure of arterial oxygen, partial pressure of venous oxygen; significant increases occurred in respiratory rate, minute volume index, diastolic arterial blood pressure, systemic vascular resistance, and arterial pH over time. We consider that the observed statistically significant cardiopulmonary changes were clinically important and that the PIVA protocol provided hemodynamic and respiratory stability for short-term anesthesia of laboratory swine.

Efficacy of a Butorphanol, Azaperone, and Medetomidine Combination for Helicopter-Based Immobilization of Bison ( Bison bison).

Decreased access to potent narcotics for wildlife applications has stimulated the need to explore alternative drug combinations for ungulate immobilizations. A combination of butorphanol, azaperone, and medetomidine (BAM) has been used for some ungulate species, but information on its use in bison ( Bison bison) is limited. We conducted field trials using BAM, in conjunction with atipamezole and naltrexone as antagonists, for reversible field immobilization of bison during ground- and helicopter-based operations. We compared times to induction and recovery, vital rates (rectal temperature and respiration rate), and the quality of induction, immobilization, and recovery between ground- and helicopter-based immobilizations of bison. Overall, 15 of 21 bison were induced with the volume we used (mean±SD=3.4±0.6 mL); two other animals darted from a helicopter required a full second dose, and four others (two darted from the ground and two from a helicopter) required a supplemental partial dose to achieve induction. All immobilizations achieved a sufficient plane of anesthesia to permit minor invasive procedures (e.g., skin biopsy and blood sampling). All animals recovered, and most (17 of 21) were reversed in ≤5 min. The mean time to induction was 10.8±7.3 min while that for recovery was 5.0±2.1 min. We found few differences in vital rates or the quality of immobilizations between ground- and helicopter-based captures. The drug combination provided good immobilization and was reliably reversed; however, inconsistent inductions at the doses we used may limit its use in field immobilizations of bison, particularly those animals being darted from a helicopter.

THE USE OF KETAMINE-XYLAZINE OR BUTORPHANOL-AZAPERONE-MEDETOMIDINE TO IMMOBILIZE AMERICAN BLACK BEARS ( URSUS AMERICANUS).

Wildlife anesthetic protocols must offer rapid inductions and recoveries, be physiologically safe, and be minimally regulated. With this in mind, we evaluated differences in induction and recovery times and physiological parameters in 33 American black bears ( Ursus americanus) anesthetized with ketamine-xylazine (KX) or immobilized with a commercial drug combination of butorphanol, azaperone, and medetomidine (BAM). Dose was based on mass estimated from field observations. Bears were housed at Appalachian Bear Rescue, Townsend, Tennessee, US, or free-ranging within the Great Smoky Mountains National Park (Tennessee and North Carolina, US) and chemically immobilized for management purposes. From 11 April to 29 June 2016, we immobilized bears with injection via pole syringe or disposable dart projected from an air-powered dart rifle. Once immobilized, we measured each bear's temperature, respiration (breaths/min), heart rate (beats/min), hemoglobin oxygen saturation (via pulse oximetry), arterial blood gases, and mass (kg). We found no differences in the induction parameters, partial pressures of CO2, and rectal temperatures. The BAM-treated bears had lower heart and respiratory rates that led to lower hemoglobin oxygen saturation levels (from blood gas analysis, SaO2). The SaO2 after treatment with BAM (91.1±0.8%) was lower than with KX (93.4±0.9%). After handling, we reversed KX-treated bears with a x̄=0.2±0.02 mg/kg yohimbine and BAM-treated bears with x̄=1.5±0.1 mg/kg atipamezole and 0.8±0.1 mg/kg naltrexone. We found no differences in the recovery times to increased respiration and to the bear assuming a head-up position. The BAM-treated bears stood and recovered quicker than did KX-treated animals. Based on our observations, BAM appears to offer safe, predictable immobilizations with fewer drawbacks and faster recovery times than KX-treated bears.

A Mixture of Butorphanol, Azaperone, and Medetomidine for the Immobilization of American Beavers ( Castor canadensis).

A total of 58 American beavers ( Castor canadensis) was immobilized with butorphanol, azaperone, and medetomidine (BAM) for the purpose of health assessments, sex determination, and placement of very high-frequency tail transmitters in a subset of animals. Isoflurane gas anesthesia was available to aid with induction when needed, and all animals received supplementary oxygen. Thirty-one beavers immobilized with a mean (SD) dose of 0.65 (0.15) mg/kg butorphanol, 0.22 (0.05) mg/kg azaperone, and 0.26 (0.06) mg/kg medetomidine did not require supplemental isoflurane during induction and the mean induction time was 8 min (range: 3-21 min). This dose was equivalent to 0.024 (0.005) mL of BAM per kilogram. A total of 29 beavers that were immobilized with a mean (SD) of 0.51 (0.07) mg/kg butorphanol, 0.17 (0.02) mg/kg azaperone, and 0.2 (0.03) mg/kg medetomidine needed supplementary isoflurane at 5% and 5 L/min for <1 min to induce full anesthesia. In none of the beavers did BAM alone provide sufficient depth of anesthesia to drill a hole in the tail for transmitter placement, and supplementary isoflurane was administered to reach a sufficient level of analgesia for the procedure. The beavers were reversed with 5 mg of atipamezole per milligram of medetomidine and 1 mg of naltrexone per milligram of butorphanol. No adverse effects or mortalities were observed. Butorphanol-azaperone-medetomidine can be considered safe for use in American beavers for minor procedures.

Butorphanol-Azaperone-Medetomidine for the Immobilization of Captive Caribou ( Rangifer tarandus granti) in Alaska, USA.

A combination of butorphanol-azaperone-medetomidine was used to immobilize four captive caribou ( Rangifer tarandus granti) in Palmer, Alaska, US. The average induction time for this combination was 5:17±2:06 min. Inductions were smooth, and recoveries were excellent. This drug combination may provide an alternative to the use of potent opioids for immobilizing caribou.