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Etorphine based immobilization protocols are reported to be effective in pronghorn; however, information on cardiorespiratory effects is limited. The objective of this study was to evaluate the efficacy and cardiopulmonary effects of etorphine, medetomidine, midazolam, and azaperone for immobilization in captive pronghorn. Additionally, the effects of endotracheal intubation and manual ventilation on cardiopulmonary variables were assessed. A combination of 5 mg etorphine, 10 mg medetomidine, 2.5 mg midazolam, and 5 mg azaperone was administered by hand or via dart to 10 pronghorn. Five pronghorn were endotracheally intubated once recumbent and manually ventilated. Oxygen at a flow of 6 L/min was supplemented to all animals. Induction and recovery times were recorded, and during recumbency vital parameters and arterial blood samples were collected. Time to lateral recumbency was 3.8 ± 1.25 min. Marked hypoxemia and hypercapnia was observed in both spontaneously breathing and manually ventilated pronghorn. Hypercapnia improved significantly in manually ventilated pronghorn compared to spontaneously breathing animals. All pronghorn recovered rapidly after reversal with 150 mg naltrexone and 30 mg atipamezole. Administration of etorphine, medetomidine, midazolam, and azaperone resulted in excellent chemical immobilization in pronghorn. Significant hypoxemia and hypercapnia occurred and oxygen supplementation, endotracheal intubation, and manual ventilation is recommended.

Chemical immobilization is commonly used to capture and handle free-ranging elk (Cervus canadensis). Butorphanol-azaperone-medetomidine (BAM) and nalbuphine-medetomidine-azaperone (NalMed-A) are compounded drug combinations that are lower-scheduled in the US than drugs historically used for elk immobilizations. We compared BAM and NalMed-A for immobilization of free-ranging elk using free-darting and Clover trapping. From January 2020 to April 2022, 196 female elk were immobilized in Pennsylvania, USA. We report vital rates, induction and recovery times, and the need for supplemental drugs. We built mixed-effects logistic regression models to describe differences between drug choice based on induction and recovery times, capture method, and individual variation. Several models were competing, including our null model, which suggests that BAM and NalMed-A are comparable based on the parameters we evaluated. Supplemental drug administration was more frequently needed in NalMed-A immobilizations (21.2%) than in BAM immobilizations (9.0%). Overall, we found minor differences between BAM and NalMed-A, both of which appear to be effective for immobilizing elk in both free-darting and Clover trapping scenarios when performing moderately invasive, minimally painful procedures on free-ranging elk., (© Wildlife Disease Association 2024.)

Administration of butorphanol, azaperone, and medetomidine (BAM) for immobilization of black howler monkeys ( Alouatta pigra ) has not been previously reported. In this observational study, 0.02 ml/kg of compounded BAM (butorphanol 27.3 mg/ml, azaperone 9.1 mg/ml, medetomidine 10.9 mg/ml) was administered IM in 10 captive black howler monkeys. Time to immobilization was recorded, an arterial blood gas performed, and at 5-min intervals, HR, RR, oscillometric arterial blood pressure, SPO 2, and rectal temperature were measured. Naltrexone and atipamezole were administered IM at procedure completion and recovery times were recorded. If invasive procedures such as surgery were necessary and additional drugs needed, further data from that individual was removed from data analysis. Final BAM dosages were 0.55 ± 0.12 mg/kg butorphanol, 0.19 ± 0.04 mg/kg azaperone, and 0.22 ± 0.05 mg/kg medetomidine. Nine of 10 monkeys achieved sedation allowing for physical exam, venipuncture, and tuberculin skin testing within 4 ± 2 min. No monkeys reached a plane of immobilization allowing for intubation. Physiologic variables were acceptable for this species. Hypoxemia (SPO 2 < 95%) was observed in three monkeys via pulse oximetry, and normoxemia was observed on arterial blood gas. Recovery was smooth and rapid. Therefore, BAM is a viable option for noninvasive procedures or as a premedication prior to induction of anesthesia in black howler monkeys.

Immobilization kits including butorphanol-azaperone-medetomidine (BAM) and nalbuphine-azaperone-medetomidine can provide effective, safe, and easy-to-use protocols in bears. Nalbuphine-azaperone-medetomidine is not commercially available but may be useful for wildlife agencies because it does not contain controlled substances. This study directly compared BAM to nalbuphine-azaperone-medetomidine immobilization in 10 juvenile healthy black bears (10 mo old; four females, six males) undergoing prerelease examinations after rehabilitation. Bears were immobilized via remote delivery of 1 mL of BAM (n=5) or nalbuphine-azaperone-medetomidine (n=5) intramuscularly in the shoulder during December (randomized, blinded trial). Bears were intubated, monitored with an electrocardiogram, pulse oximeter, capnograph, noninvasive blood pressure cuff, and rectal thermometer, and underwent physical examination, sample collection, morphometrics, and ear-tag placement. Induction, physiologic, and recovery parameters were recorded, including arterial blood gas analysis. The anesthetic agents were antagonized with atipamezole and naltrexone. There were no differences between protocols in induction or recovery times. There were no differences between protocols in heart rate, respiratory rate, temperature, oxygen saturation, end-tidal CO2, mean arterial pressure, or blood gas analysis or any differences between male and female bears in any parameters. Bears were hypertensive and normoxemic with low oxygen saturation via pulse oximeter, but all recovered smoothly and were released within 2 h of recovery. This study supports that nalbuphine-azaperone-medetomidine is clini-cally as safe and effective as BAM in American black bears., (© Wildlife Disease Association 2024.)

Raccoons (Procyon lotor) are frequently handled using chemical immobilization in North America for management and research. In a controlled environment, we compared three drug combinations: ketamine-xylazine (KX), butorphanol-azaperone-medetomidine (BAM), and nalbuphine-medetomidine-azaperone (NalMed-A) for raccoon immobilization. In crossover comparisons, raccoons received a mean of the following: 8.66 mg/kg ketamine and 1.74 mg/kg xylazine (0.104 mL/kg KX); 0.464 mg/kg butorphanol, 0.155 mg/kg azaperone, and 0.185 mg/kg medetomidine (0.017 mL/kg BAM); and 0.800 mg/kg nalbuphine, 0.200 mg/kg azaperone, and 0.200 mg/kg medetomidine (0.020 mL/kg NalMed-A). Induction time was shortest with KX (mean±SE, 10.0±0.7 min) and longest with NalMed-A (13.0±1.3 min). A sampling procedure was completed on 89% (16/18), 72% (13/18), and 89% (16/18) of the raccoons administered KX, BAM, and NalMed-A, respectively. Reasons for incomplete sampling included inadequate immobilization (one KX and one NalMed-A), responsive behaviors (one each with KX, BAM, NalMed-A), or animal safety (four BAM). Mean recovery time for KX was 32.8±7.1 min without antagonizing and 28.6±5.2 min following delivery of an antagonist. Mean recovery time was 6.2±0.8 min for BAM and 5.1±0.5 min for NalMed-A after antagonizing. Only with KX were raccoons observed to recover without use of an antagonist. Supplemental oxygen was provided to 23% (3/13), 72% (13/18), and 71% (12/17) of raccoons immobilized with KX, BAM, and NalMed-A, respectively. Hypoxemia at <80% oxygen saturation occurred in 0% (0/17), 27% (4/15), and 6% (1/16) of the raccoons administered KX, BAM, and NalMed-A, respectively; all raccoons fully recovered from chemical immobilization. All combinations could be used for raccoon immobilization; however, the need for delivery of supplemental oxygen to a majority of raccoons immobilized with BAM and NalMed-A may limit broader use of these agents for certain field studies involving capture, sample, and release of free-ranging animals from a practical standpoint., (© Wildlife Disease Association 2024.)

We evaluated a combination of nalbuphine HCl (40 mg/mL), azaperone tartrate (10 mg/mL), and medetomidine HCl (10 mg/mL), a combination known as NAM or NalMed-A, in 23 ringtails (Bassariscus astutus) during 29 handling events for a radio-collaring study in southern Oregon, US, from August 2020 to March 2022. The combination was delivered to ringtails by hand injection at 0.075 mL NAM per estimated 1 kg body mass. The mean (± standard deviation, SD) dosage calculated post hoc was 3.366 (±0.724) mg/kg nalbuphine, 0.841 (±0.181) mg/kg medetomidine, and 0.841 (±0.181) mg/kg azaperone. All captured ringtails were effectively immobilized with a mean (SD) induction time of 13.24 (±3.57) min. The medetomidine and nalbuphine components were antagonized with a combination of atipamezole and naltrexone HCl with a mean (SD) recovery time of 2.48 (±1.94) min. This combination appeared to be safe and effective for immobilizing ringtails with a low volume dose, smooth antagonism, and rapid recovery. In addition, NAM does not contain any drugs that are US Drug Enforcement scheduled, which makes it useful for immobilization procedures by wildlife professionals in the US., (© Wildlife Disease Association 2023.)

Sable antelope ( Hippotragus niger ), a large, dominant species, often require chemical immobilization for captive management. Despite several recorded protocols, limited objective or subjective data are available to guide chemical immobilization of this species. This study retrospectively compared immobilization drug combinations of carfentanil-xylazine (CX), thiafentanil-xylazine (TX), etorphine-xylazine (EX), carfentanil-acepromazine (CA), and butorphanol-azaperone-medetomidine (BAM) for healthy sable antelope at one institution. Clinically applicable physiologic measures, subjective ratings, and timing of anesthetic milestones of 161 events for 107 individuals revealed the following statistically significant findings ( P < 0.05). Induction ratings were best for TX, highest degree of muscle relaxation occurred with BAM and TX, and anesthetic ratings were best for TX and EX. Time to recovery was longest and complications 2.56 times more likely with CX. Time to recumbency was shortest in TX. Heart rate was highest in CA and lowest in BAM. For immobilization procedures, this study suggests TX would be the preferred combination for H. niger . However, all drug combinations evaluated can be used successfully to immobilize H. niger, and certain combinations may be situationally preferred based on desired muscle relaxation, expected induction or recovery times, or anticipated procedure length.

Chemical immobilization is widely used by wildlife and veterinary professionals for the safe handling of animals. A combination of nalbuphine (40 mg/mL), azaperone (10 mg/mL), and medetomidine (10 mg/mL), known as NAM, is a low-volume combination with field immobilization practicality and fewer regulations restricting its use in the US than some other drug combinations. We evaluated the safety and effectiveness of NAM as an immobilizing agent for raccoons (Procyon lotor). From May 2021 to February 2022, 16 adult raccoons were captured in cage traps and immobilized with 0.3 mL NAM intramuscularly (12 mg nalbuphine, 3 mg medetomidine, and 3 mg azaperone, regardless of body weight). After administration, time to sedation was measured; body temperature, heart rate, respiratory rate, and oxygen saturation were monitored and recorded every 5 min for 20 min. Each raccoon was weighed; the dose administered was calculated (range 2.2-4.1 mg/kg, mean 3 mg/kg). Mean induction time was 6 min (4-17 min); time to recovery following administration of 15 mg atipamezole, 7.5 mg naltrexone for reversal, was 10 min (6-18 min). Heart rate, oxygen saturation, and respiration rate remained steady during immobilization. Rectal temperature steadily declined. Overall, NAM appeared to be a practical option for raccoon immobilization, providing rapid induction and reversal as well as adequate sedation for short-term handling and minimally invasive sampling., (© Wildlife Disease Association 2023.)

A combination of tiletamine-zolazepam, medetomidine, and azaperone was used to immobilize captive Chacoan peccaries (Catagonus wagneri) for health assessments and biological sample collection at the Centro Chaqueño para la Conservación e Investigación (CCCI) in the Paraguayan Chaco during July in 2017 and 2018. In total, 83 peccaries kept in 0.25-1.50 hectare enclosures were immobilized via dart-administered anesthetic. Mean animal weight was 33.89±3.74 kg (standard deviation; n=77). The mean intramuscular (IM) anesthetic drug and dosages were 0.03±0.00 mg/kg of medetomidine, 0.91±0.10 mg/kg of Zoletil 50 (tiletamine-zolazepam), and 0.30±0.03 mg/kg azaperone. The mean time to recumbency after darting was 6.07±2.65 min. The mean time to reach the anesthetic plane postdarting was 10.00±2.00 min. Muscle relaxation was adequate to allow minor veterinary procedures. A mean dosage of 0.15±0.02 mg/kg of atipamezole was given IM to reverse the medetomidine. Recoveries were smooth and animals were standing by 59.17±30.18 min postreversal. Full recovery and release back to enclosures occurred 90±30 min postreversal. A single dose of this drug combination provided adequate anesthesia for 88% of adult Chacoan peccaries; 12% needed a supplemental dose of tiletamine-zolazepam because of failure to receive the full dose from the anesthetic dart. Sex and age did not impact the dosage required to achieve immobilization. Confinement during recovery from anesthesia is required with this protocol. Aside from mild hypoxemia, no adverse effects from anesthesia were observed. However, oxygen supplementation as a part of this protocol is recommended to support circulatory and respiratory capacity., (© Wildlife Disease Association 2023.)

We chemically immobilized a free-ranging moose subspecies, Shiras moose (Alces alces shirasi), using a combination of butorphanol (27.3 mg/mL), azaperone (9.1 mg/mL), and medetomidine (10.9 mg/mL). Ground and helicopter darting with fixed doses of 2 mL and 3 mL, respectively, safely immobilized 13 individuals in Wyoming, USA., (© Wildlife Disease Association 2023.)

Objective: To determine the pharmacokinetics of a single bolus of intravenous (IV) propofol after intramuscular administration of etorphine, butorphanol, medetomidine, and azaperone in 5 southern white rhinoceros to facilitate reproductive evaluations. A specific consideration was whether propofol would facilitate timely orotracheal intubation., Animals: 5 adult, female, zoo-maintained southern white rhinoceros., Procedures: Rhinoceros were administered etorphine (0.002 mg/kg), butorphanol (0.02 to 0.026 mg/kg), medetomidine (0.023 to 0.025 mg/kg), and azaperone (0.014 to 0.017 mg/kg) intramuscularly (IM) prior to an IV dose of propofol (0.5 mg/kg). Physiologic parameters (heart rate, blood pressure, respiratory rate, and capnography), timed parameters (eg, time to initial effects and intubation), and quality of induction and intubation were recorded following drug administration. Venous blood was collected for analysis of plasma propofol concentrations using liquid chromatography-tandem mass spectrometry at various time points after propofol administration., Results: All animals were approachable following IM drug administration, and orotracheal intubation was achieved at 9.8 ± 2.0 minutes (mean ±SD) following propofol administration. The mean clearance for propofol was 14.2 ± 7.7 ml/min/kg, the mean terminal half-life was 82.4 ± 74.4 minutes, and the maximum concentration occurred at 2.8 ± 2.9 minutes. Two of 5 rhinoceros experienced apnea after propofol administration. Initial hypertension, which improved without intervention, was observed., Clinical Relevance: This study provides pharmacokinetic data and insight into the effects of propofol in rhinoceros anesthetized using etorphine, butorphanol, medetomidine, and azaperone. While apnea was observed in 2 rhinoceros, propofol administration allowed for rapid control of the airway and facilitated oxygen administration and ventilatory support.

Chemical immobilization of wildlife, required for many biological studies and management events, often induces hypoxemia and respiratory depression. Laryngeal mask airways (LMAs) have shown promise as an efficient method of airway protection during anesthesia. Nineteen wild bighorn sheep ( Ovis canadensis ) lambs were immobilized using an IM combination of medetomidine (0.16 ± 0.062 mg/kg), azaperone (0.20 ± 0.058 mg/kg), and alfaxalone (0.54 ± 0.21 mg/kg) via remote injection. Upon recumbency, arterial blood gas parameters, minute ventilation (V E ), tidal volume (V T ), and respiratory rate were measured before and after LMA placement. The V E and V T were measured via respirometer. Time to LMA placement, cuff pressure, cuff volume, and ease of placement were measured. Medetomidine was reversed with IM atipamezole at five times the medetomidine dose upon completion of procedures. Pre- and post-LMA measurements were compared using a t test or a Wilcoxon signed-rank test based on normality of the data. The LMA provided a patent airway in all lambs with a significant ( P < 0.0001) increase in VE (mean [95% CI]; pre-LMA: V E = 17.3 [16.2-18.5] L/min, post-LMA: V E = 19.8 [18.6-21.0] L/min) but did not have a significant impact on partial pressure of oxygen (PaO 2 ; pre-LMA: corrected PaO 2 = 45.2 [41.2-49.2] mm Hg, post-LMA: corrected PaO 2 = 47.5 [43.3-51.7] mm Hg; P = 0.19) or partial pressure of carbon dioxide (PaCO 2 ; pre-LMA: PaCO 2 = 50.4 [46.6-53.2] mm Hg, post-LMA: PaCO 2 = 51.6 [48.8-55.7] mm Hg; P = 0.035) following placement. This study demonstrated that the LMA is a viable option for airway protection in wild bighorn sheep.

We evaluated the safety and efficacy of nalbuphine (40 mg/mL), plus medetomidine (10 mg/mL), plus azaperone (10 mg/mL) under the premixed label NalMed-A. From January to March 2020, 10 aoudad (Ammotragus lervia) were immobilized via dart-gun for seven separate sampling periods for a total of 45 recorded individual immobilization events. Induction and reversal times with NalMed-A were 5.53±2.61 min and (following atipamezole administration) 5.08±2.43 min while previous studies with alpha-2 agonist-ketamine combinations gave median and average induction times of 4.6 min and 11.2 min using medetomidine-ketamine and xylazine-ketamine, respectively. Overall, NalMed-A adequately immobilized aoudad, with 13% incidence of hyperthermia and 2.22% mortality when delivered via dart., (© Wildlife Disease Association 2022.)

Abstract: The study compared immobilisation of blesbok ( Damaliscus pygargus phillipsi ) with etorphine and azaperone vs etorphine and midazolam. Twelve female blesbok, weighing 59.4 ± 2.8 kg, were used. Each animal randomly received Treatment 1 (T1) (etorphine, 0.07 ± 0.003 mg/kg + azaperone, 0.36 ± 0.02 mg/kg) and Treatment 2 (T2) (etorphine, 0.07 ± 0.003 mg/kg + midazolam, 0.20 ± 0.01 mg/kg) with a one-week washout period between treatments. Induction times were recorded followed by physiological monitoring for 45 minutes of immobilisation. Immobilisation was reversed with naltrexone (20 mg per mg etorphine). Recovery times were also recorded. Induction, immobilisation and recovery were scored with subjective measures. Inductions and recoveries did not differ between combinations, but the quality of immobilisation was significantly better with T1. Rectal temperature and blood pressure were significantly lower during T1. Both treatments resulted in severe hypoxaemia and impaired gas exchange, although overall hypoxaemia was more pronounced for T1. Animals treated with T2, however, exhibited a deterioration in respiration as the monitoring period progressed, possibly as a result of impaired ventilatory muscle function due to the effects of midazolam. Both combinations are suitable for adequate immobilisation of blesbok and should be selected based on the specific capture situation. Supplementation with oxygen is highly recommended., (Copyright© Authors.)

Objective: To compare ketamine-butorphanol-azaperone-medetomidine (KBAM) to detomidine-etorphine-acepromazine (DEA) for field anesthesia in captive Przewalski horses (Equus przewalskii)., Animals: 10 adult Przewalski horses., Procedures: A prospective randomized crossover trial was conducted. Each horse was immobilized once with KBAM (200 mg ketamine, 109.2 mg butorphanol, 36.4 mg azaperone, and 43.6 mg medetomidine) and once with DEA (40 mg detomidine premedication, followed 20 minutes later by 3.9 to 4.4 mg etorphine and 16 to 18 mg acepromazine). Both protocols were administered by IM remote dart injection with a washout period of 6 months between treatments. Selected cardiorespiratory variables and quality of anesthesia were recorded. Antagonists were administered IM (KBAM, 215 mg atipamezole and 50 mg naltrexone; DEA, 4 mg RX821002 and 100 mg naltrexone)., Results: All horses were anesthetized and recovered uneventfully. Inductions (DEA, 6.8 min; KBAM, 11.6 min; P = 0.04) and recoveries (DEA, 3.2 min; KBAM, 19.6 min; P < 0.01) were faster with DEA compared with KBAM. Quality scores for induction and recovery did not differ between protocols, but maintenance quality was poorer for DEA (P < 0.01). Clinical concerns during DEA immobilizations included apnea, severe hypoxemia (arterial partial pressure of oxygen < 60 mm Hg), muscle rigidity, and tremors. Horses treated with KBAM were moderately hypoxemic, but arterial partial pressures of oxygen were higher compared with DEA (P < 0.01)., Clinical Relevance: Captive Przewalski horses are effectively immobilized with KBAM, and this protocol results in superior muscle relaxation and less marked hypoxemia during the maintenance phase, but slower inductions and recoveries, compared with DEA.

Objective: To determine the time course and certain cardiopulmonary effects of trunk-breathing elephants immobilized with thiafentanil-azaperone., Study Design: Prospective descriptive study., Animals: A convenience sample of 10 free-ranging African elephant bulls (estimated weight range: 3000-6000 kg)., Methods: Elephants were immobilized using thiafentanil (15-18 mg) and azaperone (75-90 mg) administered by dart. Once recumbent, the respiratory rate, minute ventilation (V˙e), end-tidal carbon dioxide (Pe'CO 2 ), arterial blood pressure and heart rate were recorded immediately after instrumentation and at 5 minute intervals until 20 minutes. Arterial blood gases were analysed at the time of initial instrumentation and at 20 minutes. On completion of data collection, thiafentanil was antagonized using naltrexone (10 mg mg -1 thiafentanil; administered intravenously). A stopwatch was used to record time to recumbency (dart placement to recumbency) and time to recovery (administration of antagonist to standing). Data were compared using a one-way anova. Data are presented as mean ± standard deviation., Results: All elephants were successfully immobilized, and there were no significant changes in cardiopulmonary variables over the monitoring period. Average time to recumbency was 12.5 (± 3.9) minutes. The measured V˙e was 103 (± 30) L minute -1 . The average heart and respiratory rates over the 20 minute immobilization were steady at 49 (± 6) beats minute -1 and 5 (± 1) breaths minute -1 , respectively. The mean arterial blood pressure was 153 (± 31) mmHg. The elephants were acidaemic (pH: 7.18 ± 0.06), mildly hypoxaemic (PaO 2 : 68 ± 15 mmHg; 9.1 ± 2.0 kPa) and hypercapnic (PaCO 2 : 52 ± 7 mmHg; 6.9 ± 0.9 kPa). Average time to recovery was 2.2 ± 0.5 minutes., Conclusion and Clinical Relevance: African elephant bulls can be successfully immobilized using thiafentanil-azaperone. Recumbency was rapid, the cardiopulmonary variables were stable over time, and recovery was rapid and complete. Mild hypoxaemia and hypercapnia were evident., (Copyright © 2022 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

Background: Butorphanol-azaperone-medetomidine (BAM™) has not been evaluated in horses., Objectives: The objective of this study was to evaluate BAM™ for chemical restraint of feral horses., Study Design: Retrospective and prospective descriptive studies., Methods: Data were collected retrospectively from medical records of 28 feral horses immobilised with BAM™ over a 6-year period. Prospectively, 0.0125 mL/kg bwt of BAM™ (butorphanol 27.3 mg/mL, azaperone 9.1 mg/mL and medetomidine 10.9 mg/mL) intramuscularly (im) was administered to eight stallions via dart, and once recumbent, 1.0 mg/kg bwt ketamine was given intravenously (iv). Induction and recovery time and quality via a standardised rubric (1 = very poor; 5 = excellent) and visual analogue scale (VAS), need for additional darts, weight tape measurement and serial physiological parameters were recorded. Serial arterial blood gas analysis was performed during recumbency. Following castration, horses were given 0.1 mg/kg bwt atipamezole (25% iv and 75% im) and allowed to recover unaided., Results: Retrospectively, 28 horses were successfully immobilised with BAM™ without a major complication. Prospectively, eight horses were given a median (range) actual BAM TM dose of 0.0143 (0.0127-0.0510) mL/kg bwt. Three of eight horses needed 1, 2 or 5 additional darts. Median (range) time to recumbency was 11 (2-44) minutes. Median (range) induction (n = 4) and recovery (n = 6) scores via rubric and VAS were 5 (4-5) and 5 (5-5) and 92 (86-93) and 98 (92-99) cm, respectively. Four of seven horses were hypoxaemic at ≥1 time point with otherwise acceptable physiological parameters. Following atipamezole, median (range) time to sternal recumbency and standing was 12 (2-18) and 17 (11-52) minutes, respectively (n = 6)., Main Limitations: The sample size was small. Data could not be collected before darting or after recovery. Some data were missing from retrospective analysis., Conclusions: Intramuscular BAM™ with iv ketamine provided chemical restraint suitable for field castration of feral horses with no mortality. Hypoxaemia occurred in the majority of horses., (© 2021 EVJ Ltd.)

We describe induction time in six white rhinoceros (Ceratotherium simum) when they received etorphine intramuscularly (IM) or etorphine plus azaperone IM. The median induction time was reduced from 8.9 min for etorphine alone to 6.25 min with azaperone; however, there was no difference in immobilization quality between treatments., (© Wildlife Disease Association 2022.)

Netgun capture is a commonly used capture method for mule deer (Odocoileus hemionus) in North America. Mortalities during netgun captures are generally low, and most often caused by direct trauma and occasionally fatal capture myopathy. Capture is a stressful event for a wild animal, and subclinical capture myopathy is difficult to measure. The use of tranquilizers during netgun capture is not widespread. We compared physiologic variables from 250 netgun-captured deer (57 males and 193 females) that did or did not receive midazolam and azaperone (mean, 0.14 mg/kg; SD, 0.02 mg/kg; range, 0.08-0.21 mg/kg) at time of capture and before transporting to a processing location, with the goal of evaluating whether drug administration would improve or worsen the physiologic state of the animal. Deer were captured in association with management activities between December 2018 and March 2020, with 132 deer receiving midazolam and azaperone at time of capture. Variables recorded included chase times, time from capture to arrival at the processing location, time from capture to release, serial rectal temperatures, heart rates, respiratory rates, body condition, age, sex, O2 administration, creatine kinase, aspartate aminotransferase, packed cell volume, red blood cell concentration, and hemoglobin, as well as serial venous pH, pCO2, HCO3-, and base excess. All animals were collared with GPS tracking devices and monitored after release. There was no difference in survival after capture between deer that did or did not receive midazolam and azaperone. All animals experienced severe metabolic lactic acidosis, which generally worsened with increasing chase time, highlighting the critical importance of limiting chase times during captures. Drug administration did not influence the degree of metabolic acidosis; however, it appeared to have a favorable effect on several stress-related indices, including rectal temperature, heart rate, respiratory rate, and packed cell volume., (© Wildlife Disease Association 2022.)