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.

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.

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.

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.

Evaluation of intramuscular anesthetic protocols in healthy domestic horses.

OBJECTIVE: To assess anesthetic induction, recovery quality and cardiopulmonary variables after intramuscular (IM) injection of three drug combinations for immobilization of horses. STUDY DESIGN: Randomized, blinded, three-way crossover prospective design. ANIMALS: A total of eight healthy adult horses weighing 470-575 kg. METHODS: Horses were administered three treatments IM separated by ≥1 week. Combinations were tiletamine-zolazepam (1.2 mg kg-1), ketamine (1 mg kg-1) and detomidine (0.04 mg kg-1) (treatment TKD); ketamine (3 mg kg-1) and detomidine (0.04 mg kg-1) (treatment KD); and tiletamine-zolazepam (2.4 mg kg-1) and detomidine (0.04 mg kg-1) (treatment TD). Parametric data were analyzed using mixed model linear regression. Nonparametric data were compared using Skillings-Mack test. A p value <0.05 was considered statistically significant. RESULTS: All horses in treatment TD became recumbent. In treatments KD and TKD, one horse remained standing. PaO2 15 minutes after recumbency was significantly lower in treatments TD (p < 0.0005) and TKD (p = 0.001) than in treatment KD. Times to first movement (25 ± 15 minutes) and sternal recumbency (55 ± 11 minutes) in treatment KD were faster than in treatments TD (57 ± 17 and 76 ± 19 minutes; p < 0.0005, p = 0.001) and TKD (45 ± 18 and 73 ± 31 minutes; p = 0.005, p = 0.021). There were no differences in induction quality, muscle relaxation score, number of attempts to stand or recovery quality. CONCLUSIONS AND CLINICAL RELEVANCE: In domestic horses, IM injections of tiletamine-zolazepam-detomidine resulted in more reliable recumbency with a longer duration when compared with ketamine-detomidine and tiletamine-zolazepam-ketamine-detomidine. Recoveries were comparable among protocols.

PHYSIOLOGICAL AND ANESTHETIC EFFECTS OF HAND INJECTION VERSUS DARTING TO INDUCE ANESTHESIA IN CHIMPANZEES (PAN TROGLODYTES).

Great ape anesthesia is reported to carry a significant risk. Therefore, techniques aiming to reduce stress and increase welfare, such as hand injection of anesthesia induction agents, have received considerable attention in zoo, laboratory, and captive wildlife environments. However, there is little evidence to support the superiority of such techniques. To investigate this issue, anesthesia records of healthy zoo-housed chimpanzees (Pan troglodytes) between 2012 and 2017 in which the animal was either darted or hand injected were analyzed (n = 50). Sex, age, induction, muscle relaxation, and overall anesthesia quality as well as recovery ratings, heart rate, systolic, mean and diastolic blood pressure, respiratory rate, end-tidal CO2, oxygen saturation (SpO2), and body temperature were analyzed. Chimpanzees that were darted showed statistically significantly higher heart rate, SpO2, and body temperature than those that were hand injected. It was found that darted chimpanzees were also significantly more likely to have poorer perianesthetic muscle relaxation and overall anesthesia rating scores. This study provides further evidence that the use of hand injection can reduce factors associated with stress and improve the quality of chimpanzee anesthesia.

Physiologic and blood gas effects of xylazine-ketamine versus xylazine-tiletamine-zolazepam immobilization of white-tailed deer before and after oxygen supplementation: a preliminary study.

OBJECTIVE: To compare oxygenation and ventilation in white-tailed deer (Odocoileus virginianus) anesthetized with two treatments with and without oxygen supplementation. STUDY DESIGN: Randomized, blinded, crossover study. ANIMALS: A total of eight healthy adult white-tailed deer weighing 49-62 kg. METHODS: Each deer was anesthetized twice intramuscularly: 1) treatment XK, xylazine (2 mg kg-1) and ketamine (6 mg kg-1) and 2) treatment XTZ, xylazine (2 mg kg-1) and tiletamine-zolazepam (4 mg kg-1). With the deer in sternal position, arterial and venous blood was collected before and at 30 minutes during administration of oxygen at 1 L minute-1 through a face mask. PaO2 and heart rate (HR) were compared using two-way repeated measures anova. pH, PaCO2 and lactate concentration were analyzed using mixed-effects linear models, p < 0.05. RESULTS: When breathing air, PaO2 was < 80 mmHg (10.7 kPa) in six and seven deer with XK and XTZ, respectively, and of these, PaO2 was < 60 mmHg (8.0 kPa) in three and five deer, respectively. With oxygen supplementation, PaO2 increased to 128 ± 4 and 140 ± 5 mmHg (17.1 ± 0.5 and 18.7 ± 0.7 kPa), mean ± standard error, with XK and XTZ, respectively (p < 0.001). PaO2 was not significantly different between treatments at either time point. HR decreased during oxygen supplementation in both treatments (p < 0.001). Lactate was significantly lower (p = 0.047) with XTZ than with XK (2.2 ± 0.6 versus 3.5 ± 0.6 mmol L-1) and decreased (p < 0.001) with oxygen supplementation (4.1 ± 0.6 versus 1.6 ± 0.6 mmol L-1). PaCO2 increased in XTZ during oxygen breathing. CONCLUSIONS AND CLINICAL RELEVANCE: Treatments XK and XTZ resulted in hypoxemia, which responded to oxygen supplementation. Both treatments are suitable for immobilization of white-tailed deer under the study circumstances.

Comparison of anesthetic and cardiorespiratory effects of tiletamine-zolazepam-detomidine-butorphanol, tiletamine-zolazepam-xylazine-butorphanol, and ketamine-detomidine-butorphanol in pigs.

OBJECTIVE: To evaluate and compare the anesthetic, analgesic, and cardiorespiratory effects of tiletamine-zolazepam-detomidine-butorphanol (TZDB), tiletamine-zolazepam-xylazine-butorphanol (TZXB), and ketamine-detomidine-butorphanol (KDB) in pigs and to assess anesthetic recovery duration and quality following administration of tolazoline as a reversal agent. ANIMALS: 11 healthy 2.5-month-old castrated male Landrace mixed-breed pigs. PROCEDURES: In a randomized, blinded crossover study design, pigs received the following anesthetic combinations, IM: TZDB (tiletamine-zolazepam [3 mg/kg {1.36 mg/lb}], detomidine [0.18 mg/kg {0.08 mg/lb}], and butorphanol [0.12 mg/kg {0.05 mg/lb}]); TZXB (tiletamine-zolazepam [4 mg/kg {1.8 mg/lb}], xylazine [4 mg/kg], and butorphanol [0.2 mg/kg {0.09 mg/lb}]); and KDB (ketamine [8 mg/kg {3.63 mg/lb}], detomidine [0.18 mg/kg], and butorphanol [0.3 mg/kg {0.14 mg/lb}]). A 7-day washout period was provided between treatments. At 45 minutes of anesthesia, pigs received tolazoline (2 mg/kg [0.9 mg/lb], IM; n = 6) treatment or control (5) treatment with saline (0.9% NaCl) solution. RESULTS: All anesthetic combinations induced anesthesia. Endotracheal intubation was completed within 5 minutes after anesthetic administration in all pigs, except in 2 pigs following administration of KDB. Durations (mean ± SD) of endotracheal intubation and lateral recumbency in pigs that did not receive tolazoline were 55.3 ± 4.8 minutes, 83.8 ± 15.8 minutes, and 28.2 ± 4.5 minutes and 112.4 ± 18.7 minutes, 117.2 ± 16.7 minutes, and 79.7 ± 6.0 minutes, respectively, for the TZDB, TZXB, and KDB anesthetic treatments. Tolazoline significantly shortened the duration of anesthetic recovery for all anesthetic treatments without affecting the recovery quality. CONCLUSIONS AND CLINICAL RELEVANCE: All 3 anesthetic combinations were suitable for providing anesthesia in pigs. Tolazoline administration shortened the duration of anesthetic recovery without affecting the quality of recovery.

Tiletamine/zolazepam and dexmedetomidine with tramadol provide effective general anesthesia in rats.

Background: Tiletamine/zolazepam is a dissociative anesthetic combination commonly used in small animals but information is limited in rats. The alpha-2 agonist, dexmedetomidine, has gained popularity in laboratory animal anesthesia. Tramadol is a weak opioid mu agonist. The aim of this study was to assess whether the tiletamine/zolazepam/dexmedetomidine (ZD) combination effectively provides a surgical anesthesia plane comparable to tiletamine/zolazepam/dexmedetomidine with tramadol (ZDT) in a minor procedure in rats. Methods: Rats were induced with ZD or ZDT. After the loss of paw withdrawal, a small incision was made on the rats' left thighs as a surgical stimulus. Rats were maintained under a surgical anesthesia plane by assessing the loss of the paw withdrawal reflex for 45 minutes, then atipamezole was administered. Monitored anesthesia parameters included: (a) physiological parameters - pulse rate (PR), respiratory rate (RR), tissue oxygen saturation (%SpO2), and body temperature; (b) duration parameters - induction time, onset and duration of surgical anesthesia plane, onset of recovery, and recovery time. Results: PR was significantly lower at 10 minutes in ZD and 5 minutes in ZDT groups. No difference was observed for RR, %SpO2, and body temperature. Likewise, there were no differences for duration parameters: induction time was less than 3 minutes; onset and duration of surgical anesthesia plane were approximately 5 and 45 minutes, respectively; onset of recovery (time to move) was 51 minutes; and recovery time was 52 minutes, respectively. Conclusion: These data suggest the ZD combination provides a surgical anesthesia plane comparable to ZDT in a rat incisional pain model.

Comparison of anesthetic effects of tiletamine-zolazepam-medetomidine or ketamine-medetomidine in captive Amur leopard cats (Prionailurus bengalensis euptailurus).

OBJECTIVE: To evaluate the effects and utility of tiletamine-zolazepam-medetomidine (TZM) and ketamine-medetomidine (KM) for anesthesia of Amur leopard cats (Prionailurus bengalensis euptailurus). STUDY DESIGN: Prospective, randomized experimental trial. ANIMALS: A total of six female (3.70 ± 0.49 kg) and six male (5.03 ± 0.44 kg; mean ± standard deviation) Amur leopard cats aged 2-6 years. METHODS: Each animal was administered four protocols separated by ≥3 weeks. Each protocol included medetomidine (0.05 mg kg-1) combined with tiletamine-zolazepam (1 mg kg-1; protocol MTZLO); tiletamine-zolazepam (2 mg kg-1; protocol MTZHI); ketamine (2 mg kg-1; protocol MKLO); or ketamine (4 mg kg-1; MKHI) administered intramuscularly. At time 0 (onset of lateral recumbency) and 30 minutes, heart rate (HR), respiratory rate (fR), rectal temperature, noninvasive mean arterial pressure (MAP) and hemoglobin oxygen saturation (SpO2) were recorded. Times to onset of lateral recumbency, duration of anesthesia and time to standing were recorded. RESULTS: Overall, animals were anesthetized with all protocols within 10 minutes, anesthesia was maintained ≥57 minutes, and recovery (time from the first head lift to standing) was completed within 5 minutes. During anesthesia with all protocols, HR, fR, rectal temperature, SpO2 and MAP were 99-125 beats minute-1, 33-44 breaths minute-1, 37.6-39.4 °C, 90-95% and 152-177 mmHg, respectively. No adverse event was observed. CONCLUSIONS AND CLINICAL RELEVANCE: TZM and KM at various dosages resulted in rapid onset of anesthesia, duration of >57 minutes and rapid recovery without administration of an antagonist. Accordingly, all these combinations are useful for anesthetizing Amur leopard cats and for performing simple procedures. However, the low doses of the anesthetic agents are recommended because there was no difference in duration of anesthesia between the dose rates studied.

Effect of Xylazine-Tiletamine-Zolazepam on the Local Field Potential of the Rat Olfactory Bulb.

Neural oscillations of the mammalian olfactory system have been studied for decades. This research suggests they are linked to various processes involved in odor information analysis, depending on the vigilance state and presentation of stimuli. In addition, the effects of various anesthetics, including commonly used ones like chloral hydrate, pentobarbital, ketamine, and urethane, on the local field potential (LFP) in the olfactory bulb (OB) have been studied. In particular, the combination of xylazine and tiletamine-zolazepam has been shown to produce steady anesthesia for an extended period and relatively few adverse effects; however, their effects on the LFP in the OB remain unknown. To study those effects, we recorded the LFP in the OB of rats under xylazine-tiletamine-zolazepam anesthesia. During the period of anesthesia, the spectral powers of the 1-4, 9-16, 31-64, 65-90 frequency bands increased significantly, and that of 91-170 Hz frequency band decreased significantly, whereas no significant changes were observed in the 5-8 and 17-30 Hz ranges. These results reveal dynamic changes in the time and frequency characteristics of the LFP in the OB of rats under xylazine-tiletamine- zolazepam anesthesia and suggest that this combination of anesthetics could be used for studying oscillatory processes in the OB of rats.

Sedative and physiologic effects of tiletamine-zolazepam following buccal administration in cats.

OBJECTIVES: The aim of this study was to describe the sedative and some physiological effects of tiletamine-zolazepam following buccal administration (BA) in cats. METHODS: Seven healthy spayed European shorthair cats (three males, four females) were studied twice in this randomized, blinded, crossover study. Each cat received two doses of tiletamine-zolazepam by BA: the low-dose (LD) group consisted of 5 mg/kg of each drug, and the high-dose (HD) group consisted of 7.5 mg/kg of each. Baseline systolic blood pressure (SAP), heart rate (HR), respiratory rate (RR) and a sedation score were recorded prior to administration of each treatment. The same variables plus the percentage of hemoglobin saturated with oxygen as measured by pulse oximetry (SpO2) were recorded at predefined intervals for the next 2 h. RESULTS: All cats completed the study. No retching or vomiting were observed. Hypersalivation was observed in 0/7 and 3/7 for LD and HD groups, respectively (P = 0.2). There were significant changes in scores over time for posture, response to clippers and response to manual restraint for both groups, without differences between groups. RR, HR and SAP changed significantly over time. SAP and RR were significantly lower for the HD than for the LD group. No values for hemoglobin saturation <95% were observed. CONCLUSIONS AND RELEVANCE: BA of tiletamine-zolazepam at the doses studied here is a simple and effective method for chemical restraint in cats, where the LD group had a lower impact on SAP and RR than the HD group.