A Retrospective Comparison of Electrocardiographic Parameters in Ketamine and Tiletamine-Zolazepam Anesthetized Indian Rhesus Monkeys (Macaca mulatta).

Electrocardiographic evaluation is performed in rhesus monkeys to establish the cardiovascular safety of candidate molecules before progressing to clinical trials. These animals are usually immobilized chemically by ketamine (KTM) and tiletamine-zolazepam (TZ) to obtain a steady-state heart rate and to ensure adequate human safety. The present study aimed to evaluate the effect of these anesthetic regimens on different electrocardiographic parameters. Statistically significant lower HR and higher P-wave duration, RR, QRS, and QT intervals were observed in the KTM-anesthetized group in comparison to TZ-anesthetized animals. No significant changes were noticed in the PR interval and p-wave amplitude. Sex-based significance amongst these parameters was observed in male and female animals of TZ- and KTM-anesthetized groups. Regression analysis of four QTc formulas in TZ-anesthetized rhesus monkeys revealed that QTcNAK (Nakayama) better corrected the QT interval than QTcHAS (Hassimoto), QTcBZT (Bazett), and QTcFRD (Fridericia) formulas. QTcNAK exhibited the least correlation with the RR interval (slope closest to zero and r = .01) and displayed no statistical significance between male and female animals. These data will prove useful in the selection of anesthetic regimens for chemical restraint of rhesus monkeys in nonclinical safety evaluation studies.

Assessment of a Combination of Tiletamine/Zolazepam, Ketamine, and Dexmedetomidine for Anesthesia of Swine (Sus domesticus).

This study investigated the induction of anesthesia in swine by injection of tiletamine/zolazepam and ketamine in combination with either dexmedetomidine (TKD) or xylazine (TKX). We hypothesized that TKD would accelerate anesthesia onset and prolong recovery as compared TKX in swine undergoing a noninvasive radiographic procedure. A randomized crossover experiment was performed on 6 healthy, intact, male miniature swine undergoing radiographic examination. Swine were randomly assigned to one of 2 groups: 1) 5mg/kg tiletamine/zolazepam, 2.5mg/kg ketamine, and 0.0125mg/kg dexmedetomidine (TKD) or 2) 5mg/kg tiletamine/zolazepam, 2.5mg/kg ketamine, and 2.5mg/kg xylazine (TKX). Either TKD or TKX was administered intramuscularly at 0.05mL/kg to provide anesthesia for a 45-min radiographic procedure. At 45min after drug administration, atipamezole was administered. During anesthesia, swine were monitored for duration parameters (time to sternal recumbency [onset of anesthesia], lateral recumbency, loss of palpebral reflex, return of the palpebral reflex, and return to sternal recumbency [onset of recovery]) and physiologic parameters (heart rate, %SpO2, noninvasive blood pressure, and body temperature). Duration and physiologic parameters did not differ between groups at any time point. The results indicate TKD and TKX provide comparable general anesthesia in swine undergoing a radiographic examination.

EVALUATION OF A COMBINATION OF TILETAMINE-ZOLAZEPAM, MEDETOMIDINE, AND AZAPERONE WITH NASAL OXYGEN SUPPLEMENTATION FOR THE IMMOBILIZATION OF CAPTIVE CHACOAN PECCARIES (CATAGONUS WAGNERI) IN THE CHACO REGION OF PARAGUAY.

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.

Effect on physiological parameters and anaesthetic dose requirement of isoflurane when tramadol given as a continuous rate infusion vs a single intravenous bolus injection during ovariohysterectomy in dogs.

BACKGROUND: Tramadol produces a significant reduction in both sevoflurane and isoflurane minimum alveolar concentrations in dogs under experimental conditions. This study aims to compare the effects of tramadol administered as a constant rate infusion (CRI) with those of tramadol administered as a single intravenous bolus on physiological parameters and isoflurane requirements in dogs undergoing ovariohysterectomy. METHODS: In this study, forty female dogs undergoing ovariohysterectomy were enrolled. The bitches were anesthetized with 5 mg/kg of tiletamine/zolazepam combined with 0.05 mg/kg of acepromazine intravenously. Anesthesia was maintained with isoflurane delivered in 100% oxygen. The group A (n = 20) received tramadol 4 mg/kg in a single intravenous bolus, whereas the group B (n = 20) received tramadol 1.5 mg/kg in an intravenous bolus followed by tramadol 2.6 mg/kg/h as a CRI. The following parameters were recorded: heart rate, respiratory rate, non-invasive blood pressure, body temperature, EtCO2, SpO2 and inspired and expired concentrations of isoflurane. Parameter measurements were performed from pre-preedication (baseline) to skin suturing. RESULTS: The dogs were healthy subjects that demonstrated no abnormalities on laboratory investigations. Significant tachycardia was recorded after administration of tiletamine/zolazepam combined with acepromazine in both groups. Heart rate decreased after intubation but remained significantly higher compared to baseline values in both groups. Systolic blood pressure significantly decreased in both groups but the recorded values were within the physiological range. Mild reduction in body temperature was recorded in both groups. SpO2 and EtCO2 remained within the physiological range. Isoflurane requirement was significantly lower in the group B compared to the group A. Transient twitching was recorded in two dogs belonging to the group A after tramadol administration. CONCLUSIONS: Compared to tramadol given as a single intravenous bolus injection during ovariohysterectomy in dogs, tramadol administered as a CRI reduces isoflurane requirements in dogs anesthetized with tiletamine/zolazepam combined with acepromazine. Both tramadol given as a CRI and a single intravenous bolus injection, induce decrease in heart rate, respiratory rate and in body temperature but the values of these parameters remain within physiological range in dogs undergoing ovariohysterectomy.

Cardiorespiratory effects of isoflurane and medetomidine-tiletamine-zolazepam in 12 bonobos (Pan paniscus).

BACKGROUND: Cardiovascular disease is a significant cause of mortality in captive great apes. However, data from bonobos are lacking due to a paucity of collections in Europe. Comprehensive preventive screening is required to understand the aetiopathogenesis of cardiovascular disease, but the provision of a stable and predictable anaesthetic protocol with minimal cardiovascular effects is challenging. METHODS: This prospective, observational case series reports anaesthesia of 12 bonobos using hand-injected medetomidine and tiletamine-zolazepam followed by maintenance with isoflurane in oxygen. Comprehensive clinical examinations, including arterial blood gases and echocardiography were undertaken. RESULTS: Induction of anaesthesia with hand injection was successful in all but one individual. Respiratory acidosis with metabolic alkalosis and respiratory alkalosis with metabolic acidosis were documented. Hypochloraemia may have contributed to non-respiratory alkalosis in one individual. Ten bonobos experienced hypotension and required haemodynamic support. Both N-terminal pro b-type natriuretic peptide and troponin I cardiac biomarkers correlated with left ventricular ejection fraction (percentage). Recovery was smooth, rapid and uneventful in all animals. LIMITATIONS: The effects of the anaesthetic must be considered during echocardiographical interpretation. CONCLUSIONS: The anaesthesia protocol provided a safe, predictable induction and recovery, facilitating diagnostics (including echocardiography) and minor surgical procedures. Comprehensive monitoring, including invasive blood pressure monitoring and haemodynamic support, is highly recommended.

Rising abuse of veterinary drugs.

ABSTRACT: There has been a significant increase in veterinary drugs found on toxicology screens and postmortem analyses, especially in the Northeast region of the US. This article details the effects and treatment of two common culprits: xylazine and tiletamine-zolazepam.

Comparison of intratesticular and intramuscular administration of zolazepam-tiletamine combination on sedation, induction, and recovery qualities and vital variables in cats undergoing castration: a prospective, randomized, clinical study.

This study was aimed to compare the effects of intratesticular (IT) and intramuscular (IM) administration of the zolazepam-tiletamine (ZT) combination on sedation, induction, and recovery qualities and vital variables in cats undergoing castration. Fourteen clinically client-owned healthy cats were randomly assigned to receive 10 mg/kg ZT by either IT or IM routes. Temperament score, injection reaction score, induction time, intubation time, surgical length, anesthesia time, recovery time, and full recovery time were evaluated. Sedation score, heart rate (HR), respiratory frequency (fR), peripheral hemoglobin oxygen saturation (SpO2), mean arterial pressure (MAP), and rectal temperature (RT) variables were assessed at baseline (T0), T5, T10, T15, and T30. Median temperament score and injection reaction score were not different between groups. Induction time was significantly (p = 0.0244) shorter for the IT group (142.6 ± 29.9) than IM (290 ± 48.7 seconds). Length of anesthesia was longer in the IM group (median 290; ranged 120-540 minutes) than the IT group (median 140; ranged 98-180 minutes) (p = 0.0279). Time to standing and time to full recovery were significantly shorter in IT than IM. A recovery quality score did not significantly differ between groups (p = 0.2268). No statistically significant differences were detected between IT and IM administration regarding sedation score, HR, SpO2, MAP, and RT. The IT administration of 10 mg/kg ZT induces shorter onset of sedation and recovery time than IM administration, thereby it can be suggested for cats undergoing castration. Both administration routes produce effective sedation with limited physiological changes in anesthesia variables.

Ketamine-medetomidine compared to tiletamine-zolazepam-medetomidine for immobilisation of semi-captive cheetahs (Acinonyx jubatus).

ABSTRACT: The immobilisation time and cardiopulmonary effects of ketamine-medetomidine (KM) and tiletamine-zolazepam-medetomidine (TZM) were compared in semi-captive cheetahs (Acinonyx jubatus). Seven healthy adult cheetahs were included in a randomised prospective crossover study. Each cheetah was immobilised on two occasions by remote injection, once with a combination of ketamine (4.93 ± 0.75 mg/kg) and medetomidine (0.038 ± 0.003 mg/kg) (KM) and once with tiletamine-zolazepam (1.16 ± 0.12 mg/kg) and medetomidine (0.039 ± 0.002 mg/kg) (TZM). Time to safe approach, characterised by absent responses to an ear flick and tail tug, was recorded as the immobilisation time. Following immobilisation, cardiopulmonary parameters were recorded, and an arterial blood gas sample analysed. Data is reported as mean ± SD and compared using a general linear mixed model (p < 0.05). Immobilisation times were no different between combinations, 11.4 ± 5.7 minutes for KM and 13.2 ± 4.6 minutes for TZM (p = 0.528). Systolic blood pressure was 218 ± 22 mmHg for KM and 210 ± 28 mmHg for TZM (p = 0.594). There was moderate hypoxaemia with both combinations with arterial oxygen partial pressure of 58.4 ± 6.6 mmHg for KM and 61.3 ± 4.2 mmHg for TZM (p = 0.368). Haematocrit was higher with KM (40.7 ± 2.5) than TZM (35.8 ± 2.8, p = 0.007). There were differences in electrolytes, with TZM resulting in higher serum potassium (4.3 ± 0.2 mmol/L, p < 0.001) and glucose (11.8 ± 2.9 mmol/L, p = 0.039) than KM. Both combinations provided acceptable immobilisation for field use, although severe hypertension was a consistent finding. Supplementation with oxygen is recommended with both combinations.

Comparison of cardiorespiratory and anesthetic effects of ketamine-midazolam-xylazine-sufentanil and tiletamine-zolazepam-xylazine in miniature pigs.

Effective and adequate anesthesia is conducive to better restrain for pigs during surgical or diagnostic procedures This study aimed to evaluate cardiorespiratory and anesthetic effects of ketamine-midazolam-xylazine-sufentanil or tiletamine-zolazepam-xylazine as general anesthetics in miniature pigs. In phase 1, one of the combinations was administered intramuscularly to miniature pigs. The KMXS protocol combined 10 mg kg-1 ketamine, 0.5 mg kg-1 midazolam, and 2 mg kg-1 xylazine with 2 µg kg-1 sufentanil. The TZX protocol combined 2.2 mg kg-1 tiletamine, 2.2 mg kg-1 zolazepam, and 1.4 mg kg-1 xylazine. After treatment, the mean arterial pressure, systolic arterial pressure, diastolic arterial pressure, heart rate, respiratory rate, peripheral hemoglobin oxygen saturation, rectal temperature, and anesthesia quality were recorded. In phase 2, the feasibility of KMXS and TZX as general anesthetics were evaluated for pig castration. In phase 1, both drug combinations provided smooth induction with similar anesthetic effects. The KMXS protocol provided moderate anesthesia for 60-70 minutes in pigs, while the TZX protocol provided 30-45 minutes. In phase 2, castration was completed smoothly in all pigs with little fluctuation in physiological variables. The KMXS protocol is better for medium-term anesthesia, while the TZX protocol is preferable for short-term anesthesia in pigs.

Effect of season and diet on heart rate and blood pressure in female red deer (Cervus elaphus) anaesthetised with medetomidine-tiletamine-zolazepam.

Temperate zone ungulates like red deer (Cervus elaphus) show pronounced seasonal acclimatisation. Hypometabolism during winter is associated with cardiovascular changes, including a reduction in heart rate (fH) and temporal peripheral vasoconstriction. How anaesthesia with vasoactive substances such as medetomidine affect the seasonally acclimatised cardiovascular system is not yet known. We anaesthetised eleven healthy female red deer with medetomidine (0.1 mg/kg) and tiletamine/zolazepam (3 mg/kg) twice in winter (ad libitum and restricted feed) and in summer (ad libitum and restricted feed), with a two-week washout-period in-between, to test for the effect of season, food availability and supplementation with omega-3 or omega-6 polyunsaturated fatty acid (PUFA) on fH and arterial blood pressure (ABP) during anaesthesia. Six animals received pellets enriched with omega-6 fatty acids (FA), and five animals with omega-3 FA. Anaesthesia significantly decreased fH in summer but not in winter and ABP was lower in winter (p < 0.05). The combination of omega-6 FA enriched pellets and food restriction resulted in a lower fH and higher ABP during anaesthesia with more pronounced changes in winter (p < 0.001). Our results demonstrate that season, food availability and type of PUFA supplementation in red deer affect the cardiovascular system during anaesthesia.

Fast and Sensitive Method for the Determination of 17 Designer Benzodiazepines in Hair by Liquid Chromatography-Tandem Mass Spectrometry.

In recent years, identification and analysis of designer benzodiazepines have become a challenge in forensic toxicology. These substances are analogs of the classic benzodiazepines, but their pharmacology is not well known, and many of them have been associated with overdoses and deaths. As a result, there has been a surge in efforts to develop analytical methods to determine these compounds in different biological samples. Our aim was to develop and validate a fast, sensitive and specific method for determining 17 designer benzodiazepines (adinazolam, clobazam, clonazolam, delorazepam, deschloroetizolam, diclazepam, etizolam, flualprazolam, flubromazepam, flubromazolam, flunitrazolam, N-desmethylclobazam, nifoxipam, nitrazolam, meclonazepam, pyrazolam and zolazepam) in hair by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Hair samples were decontaminated and pulverized, and a 20 mg aliquot was incubated in methanol in an ultrasound bath (1 h, 25°C). The supernatant was evaporated and reconstituted in 200 µL of mobile phase, and the extracts were filtered (nano-filter vials) before injection into LC-MS-MS. All analytes were eluted from the chromatographic column in 8 min, and two multiple-reaction monitoring (MRM) transitions were used to identify each compound. The limits of quantification were 5 or 25 pg/mg depending on the analyte, and the calibration functions were linear to 200 pg/mg. Imprecision was <19.2% (n = 15), and bias was from -13.7 to 18.3% (n = 15). All the analytes yielded high extraction efficiencies >70% and displayed ion suppression between -62.8% and -23.9% (n = 10). The method was applied to 19 authentic cases. Five samples were positive for flualprazolam ( 200 pg/mg) and/or etizolam (47.4-88.5 pg/mg). In conclusion, the present validated method has proven to be fast, sensitive, specific and capable of determining 17 designer benzodiazepines in hair using LC-MS-MS.

Comparison of Alfaxalone-Midazolam, Tiletamine-Zolazepam, and KetamineAcepromazine Anesthesia during Plethysmography in Cynomolgus Macaques (Macaca fascicularis) and Rhesus Macaques (Macaca mulatta).

Plethysmography is used in nonhuman primates (NHPs) to measure minute volume before aerosol exposure to an agent to calculate total time necessary in the exposure chamber. The consistency of respiratory parameters during the entire exposure time is paramount to ensuring dosing accuracy. Our study sought to validate an alfaxalone-midazolam (AM) anesthetic combination for use in aerosol studies. We hypothesized that AM would provide an adequate duration of anesthesia, achieve and maintain steady state minute volume (SSMV) for 20 min, and have anesthetic quality and side effects comparable to or better than either tiletamine-zolazepam (TZ) and ketamine-acepromazine (KA), the most common anesthetics used for this purpose currently. Two groups of NHPs, one consisting of 15 cynomolgus macaques and one of 15 rhesus macaques, received 3 intramuscular anesthetic combinations (AM, TZ, and KA), no less than one week apart. Anesthetized NHPs were placed in a plethysmograph chamber and their minute volumes were measured every 10 s to determine whether they had achieved SSMV and maintained it for at least 20 consecutive min. Achieving and reliably maintaining an SSMV for at least 20 min facilitates precise aerosol dosing of a challenge agent. Quality of anesthesia, based on the NHP's ability to achieve and maintain SSMV, was higher with AM compared with TZ and KA in both species, and AM had a longer duration of SSMV as compared with TZ and KA in cynomolgus macaques. Average SSMV was larger with AM compared with TZ in cynomolgus macaques, but larger with KA compared with AM in rhesus macaques. Duration of anesthesia was sufficient with all combinations but was longer for TZ than both AM and KA in both species. These results suggest that the AM anesthetic combination would produce the most accurate dosing for an aerosol challenge.

Reduction of greenhouse gases emission through the use of tiletamine and zolazepam.

Isoflurane is an anaesthetic gas widely used in both human and veterinary medicine. All currently used volatile anaesthetics are ozone-depleting halogenated compounds. The use of total intravenous anaesthesia (TIVA) allows to induce the effect of general anaesthesia by administering drugs only intravenously without the use of anaesthetic gases. This allows you to create a protocol that is safe not only for the patient, but also for doctors and the environment. However, so far, no anaesthetic protocol based on induction of anaesthesia with tiletamine-zolazepam without the need to maintain anaesthesia with anaesthetic gas has been developed. Our study showed that the use of this combination of drugs for induction does not require the use of additional isoflurane to maintain anaesthesia. Thanks to Dixon's up-and-down method we proved that with the induction of anaesthesia with tiletamine-zolazepam at a dose of 5 mg/kg the use of isoflurane is not needed to maintain anaesthesia in minimally invasive surgical procedures. Until now, this dose has been recommended by the producer for more diagnostic than surgical procedures or for induction of general anaesthesia. The maintenance was required with anaesthetic gas or administration of another dose of the tiletamine-zolazepam. The results obtained in this study will allow for a significant reduction in the consumption of isoflurane, a gas co-responsible for the deepening of the greenhouse effect, having a negative impact on patients and surgeons. These results are certainly the first step to achieving a well-balanced and safe TIVA-based anaesthetic protocol using tiletamine-zolazepam, the obvious goal of which will be to maximize both the safety of the patient, people involved in surgical procedures, and the environment itself. Being aware of the problem of the greenhouse effect, we are committed to reducing the consumption of anaesthetic gases by replacing them with infusion agents.

Clinical Usefulness of the Anaesthetic Protocol Using Low Doses of Tiletamine - Zolazepam Combination in Continuous Rate Infusion as a Partial Intravenous Anaesthesia in Bitches Undergoing Laparoscopic Surgery.

The objective of this study was to evaluate the clinical usefulness of the combination of tiletamine-zolazepam used in low doses as a continuous rate infusion in a partial intravenous anesthesia protocol. Fifteen clinically healthy, different breed bitches weighing 25.08 ± 10.39 kg was used in this study. After a food fast for at least 12 hours and water fast for 4 hours, the animals were premedicated with dexmedetomidine. After 15 minutes, the bolus of tiletamine-zolazepam combination was given as an. Induction of general anesthesia, immediately followed by continuous intravenous infusion. The following parameters were measured immediately after the induction of general anesthesia and lasted until the end of the surgery: electrocardiography, heart rate, systolic arterial blood pressure, diastolic arterial blood pressure, mean arterial blood pressure, body temperature respiratory rate end tidal of CO2. During the recovery period, pain level was evaluated as well as sedation assessment. Time for successful intubation after administration of the tiletamine-zolazepam combination was within 3 minutes. Heart rate was within reference values. Systolic, diastolic, and mean arterial blood pressure were also within the reference values. Internal body temperature showed a downward trend for a whole procedure time. During recovery, only 1 patient showed symptoms of pain and signs of dissociation. In summary, the partial intravenous protocol with the use of tiletamine-zolazepam combination and low anesthetic gases concentration is clinically useful because of ensuring the correct level of anesthesia and stability of intraoperative parameters as well as a good recovery period.

Determination of the effective dosage of tiletamine-zolazepam-ketamine-xylazine, with or without methadone, in dogs.

OBJECTIVE: To determine the effective dosage of the combination tiletamine-zolazepam-ketamine-xylazine (TKX), with or without methadone, in dogs. STUDY DESIGN: Prospective, randomized, experimental study. ANIMALS: A total of 29 dogs. METHODS: Dogs were randomly administered TKX (group TKX, n = 13) or combined with 0.3 mg kg-1 of methadone (group TKXM, n = 16) intramuscularly. The TKX solution contained tiletamine (50 mg mL-1), zolazepam (50 mg mL-1), ketamine (80 mg mL-1) and xylazine (20 mg mL-1). The effective dosages for immobility in 50% and 95% of the population (ED50 and ED95) were estimated using the up-and-down method. Approximately 20 minutes after drug administration, a skin incision was performed and the response was judged as positive or negative if the dogs moved or did not move, respectively. The TKX volume for the subsequent dog in the same group was increased or decreased by 0.005 mL kg-1 if the response of the previous dog was positive or negative, respectively. Heart and respiratory rates, and sedation/anesthesia scores (range 0-21) were recorded before and 15 minutes after drug administration. RESULTS: Estimated ED50 and ED95 (95% confidence intervals) were: TKX, 0.025 (0.020-0.029) and 0.026 (0.010-0.042) mL kg-1; TKXM, 0.022 (0.018-0.025) and 0.033 (0.017-0.049) mL kg-1. Median (interquartile range) scores for sedation/anesthesia were 17 (16-18) and 17 (15-20), and times until lateral recumbency were 5 (4-6) and 6 (4-10) minutes in TKX and TKXM, respectively (p > 0.05). In both groups heart and respiratory rates decreased, but values remained acceptable for anesthetized dogs. CONCLUSIONS AND CLINICAL RELEVANCE: The results provide a guide for volumes of TKX and TKXM in dogs requiring restraint for minimally invasive procedures. Inclusion of methadone in the TKX combination did not influence ED50.

Anestesia total intravenosa para tratamento endodôntico em Panthera leo ­ relato de caso / Total intravenous anesthesia for endodontic treatment in Panthera leo ­ case report

Animais presentes em zoológicos frequentemente necessitam de captura e anestesia para a realização de procedimentos clínicos e cirúrgicos. A anestesia total intravenosa apresenta vantagens como redução do estresse cirúrgico e menor depressão cardiovascular e respiratória. Entretanto, ainda são escassas as pesquisas dedicadas dentro deste contexto. Nesse sentido, o objetivo deste relato foi avaliar o protocolo anestésico empregado, visando um procedimento seguro e passível de reversão para a espécie silvestre selecionada. Acompanhou-se a anestesia de um leão (Panthera leo), macho, adulto, proveniente do Zoológico Municipal de Curitiba, submetido a procedimento endodôntico. A medicação pré-anestésica constituiu-se de dexmedetomidina (6 µg/kg), metadona (0,2 mg/kg), midazolam (0,1 mg/kg) e tiletamina-zolazepam (1,2 mg/kg). A indução foi realizada com propofol (1,5 mg/kg) e o animal foi intubado. Visando promover analgesia local, foi realizado bloqueio infraorbitário esquerdo com 5 mL de lidocaína a 2%. A manutenção foi realizada por meio do fornecimento de propofol (0,02-0,1 mg/kg/h), dexmedetomidina (0,5 µg/kg/h) e remifentanil (5 µg/kg/h). O paciente apresentou sedação profunda e foi mantido em plano anestésico cirúrgico; todos os parâmetros fisiológicos monitorados permaneceram estáveis durante todo o procedimento. Após 55 minutos de anestesia o paciente apresentava sustentação espontânea da cabeça, quando foi novamente transportado ao zoológico para soltura no recinto. A ambulação foi considerada normal pelos observadores no zoológico seis horas após a anestesia. Pôde-se concluir que o protocolo realizado se mostrou tanto eficaz quanto seguro para a referida espécie encaminhada ao procedimento em questão.

Zoo animals often require capture and anesthesia in order to undergo clinical and surgical procedures. Total intravenous anesthesia has advantages such as reduced surgical stress and less cardiovascular and respiratory depression. However, specific research on this matter is still scarce. Therefore, the present report aims to evaluate the anesthetic protocol employed, seeking a safe and reversible procedure for the selected wild species. A male adult lion (Panthera leo), from the Zoológico Municipal de Curitiba, was subjected to an endodontic anesthesia, under close monitoring. The pre-anesthetic medication consisted of dexmedetomidine (6 µg/kg), methadone (0.2 mg/kg), midazolam (0.1 mg/kg) and tiletamine-zolazepam (12 mg/kg). Induction was performed with propofol (1 mg/kg) and the animal was intubated. In order to promote local analgesia, a left infraorbital block was implemented with 5 mL of 2% lidocaine. Maintenance was undertaken by supplying propofol (0.02-0.1 mg/kg/min), dexmedetomidine (0.5 µg/kg/h) and remifentanil (5 µg/kg/h). The patient exhibited deep sedation and followed the surgical anesthetic plan; all the monitored physiological parameters remained stable throughout the procedure. After 55 minutes of anesthesia the patient showed spontaneous head support, when it was transported back to the zoo. The ambulation was considered normal by the zoo observers 6 hours after the anesthesia. It was concluded that the protocol was both effective and safe for the referred species undergone the procedure reported.

Comparison of the Cardiovascular Effects of Two Medetomidine Doses Combined with Tiletamine-Zolazepam for the Immobilization of Red Deer Hinds (Cervus elaphus).

Wild animal immobilization often requires high doses of α2-adrenoceptor agonists. Despite their desired sedative and analgetic effects, well-recognized cardiovascular side effects, such as hypertension and bradycardia, remain a major concern. We compared the effect of two medetomidine doses on intra-arterial blood pressure and heart rate in 13 captive, female red deer (Cervus elaphus) immobilized during winter. Each animal was randomly assigned to receive either 80 µg/kg (group L) or 100 µg/kg (group H) medetomidine, combined with 3 mg/kg tiletamine-zolazepam administered intramuscularly. Changes in cardiovascular variables over time and differences between the groups were analyzed using linear mixed-effect models. Induction time was faster in group L compared with group H; recovery time did not differ between groups. Initially, the arterial blood pressure was higher in group H compared with group L, but differences between groups diminished during anesthesia. Moreover, the decline in arterial blood pressure in group H was more rapid. Heart rate was significantly lower in group L, but bradycardia was not observed. The higher medetomidine dose did not reduce induction time, and initial hypertension was reduced by administering the lower dose. Therefore, although the sample size was small and, thus, the significance of results might be limited, we suggest using 80 µg/kg instead of 100 µg/kg medetomidine when combined with 3 mg/kg tiletamine-zolazepam for the immobilization of female red deer.

Cardiovascular effects of intravenous vatinoxan in wild boars (Sus scrofa) anaesthetised with intramuscular medetomidine-tiletamine-zolazepam.

BACKGROUND: The potent sedative medetomidine is a commonly used adjunct for the immobilisation of non-domestic mammals. However, its use is associated with pronounced cardiovascular side effects, such as bradycardia, vasoconstriction and decreased cardiac output. We investigated the effects of the peripherally-acting alpha-2-adrenoceptor antagonist vatinoxan on cardiovascular properties in medetomidine-tiletamine-zolazepam anaesthetised wild boar (Sus scrofa). METHODS: Twelve wild boars, anaesthetised twice with medetomidine (0.1 mg/kg) and tiletamine/zolazepam (2.5 mg/kg) IM in a randomised, crossover study, were administered (0.1 mg/kg) vatinoxan or an equivalent volume of saline IV (control). Cardiovascular variables, including heart rate (HR), mean arterial blood pressure (MAP), pulmonary artery pressure (PAP), pulmonary artery occlusion pressure (PAOP) and cardiac output (CO), were assessed 5 min prior to vatinoxan/saline administration until the end of anaesthesia 30 min later. RESULTS: MAP (p < 0.0001), MPAP (p < 0.001) and MPAOP (p < 0.0001) significantly decreased from baseline after vatinoxan until the end of anaesthesia. HR increased significantly (p < 0.0001) from baseline after vatinoxan administration. However, the effect on HR subsided 3 min after vatinoxan. All variables remained constant after saline injection. There was no significant effect of vatinoxan or saline on CO. CONCLUSION: Vatinoxan significantly reduced systemic and pulmonary artery hypertension, induced by medetomidine in wild boar.

Dissociative anaesthesia in dogs and cats with use of tiletamine and zolazepam combination. What we already know about it.

This article is an attempt to gather available literature regarding the use of tiletamine and zolazepam combination in anaesthesia in dogs and cats. Although tiletamine and zolazepam mixture has been known in veterinary practice for a long time, the increased interest in these drugs has been observed only recently. Tiletamine, similarly to ketamine, is a drug which belongs to the phencyclidine group. Ketamine has considerable popularity in veterinary practice what suggests that other dissociative anaesthetic drugs, such as tiletamine, could also prove effective in cats' and dogs' anaesthetic care. Zolazepam is a widely used benzodiazepine known for its muscle relaxant and anticonvulsant properties. While conducting an electronic search for articles regarding the use of tiletamine-zolazepam combination in dogs and cats, it has been discovered that the literature on the subject (tiletamine-zolazepam combination in dogs and cats) is quite scarce. Very few articles were published after 2010. Databases used were: Google Scholar, Scopus, PubMed. Most of the adverse effects, including those affecting the cardiovascular, nervous, and respiratory systems, were strictly dose-dependent. Tiletamine-zolazepam combination can be safely used as a premedication agent, induction for inhalation anaesthesia, or an independent anaesthetic for short procedures. Contraindications using tiletamine-zolazepam mixture include central nervous system (CNS) diseases such as epilepsy and seizures, head trauma, penetrative eye trauma, cardiovascular abnormalities (hypertrophy cardiomyopathy in cats, arrythmias or conditions where increase of heart rate is inadvisable), hyperthyroidism, pancreatic deficiencies or kidney failure.