Search Results (19)

This narrative review examines the clinical application of tiletamine–zolazepam (TZ) in exotic pet and wildlife anesthesia, addressing the complexities inherent in managing a broad taxonomic spectrum with diverse physiological profiles and temperaments. As a fixed-dose combination, TZ is a cornerstone of multimodal protocols designed to achieve balanced anesthesia. Its lyophilized formulation permits reconstitution with various sedative solutions, facilitating low-volume administration, a critical requirement for the immobilization of wildlife and small exotic patients. Given the significant variability in species-specific responses and environmental influences, selecting and adapting appropriate TZ-based protocols remain a challenge for practitioners. By synthesizing heterogeneous data into expert-validated guidance, this review provides specialized and general veterinarians with practical considerations for the judicious use of TZ. Emphasis is placed on integrating TZ within multimodal protocols to mitigate arousal risks, ensure consistent immobilization, and facilitate rapid recovery. This approach seeks to optimize anesthetic outcomes and promote animal welfare across these physiologically diverse populations. Full article

Laparoscopic salpingectomy is a minimally invasive surgery that requires careful anesthetic management due to the effects of intra-abdominal gas insufflation. In this retrospective study, baboons (Papio hamadryas) were treated with two induction protocols: medetomidine–ketamine (MK; n = 16) and medetomidine–tiletamine–zolazepam (MZ; n = 12) via intramuscular injection. A laryngeal mask (LMA) was used for airway management and anesthesia was maintained with isoflurane in 100% oxygen. For statistical analysis, the following parameters were analyzed via two-way ANOVA: heart rate (HR), respiratory rate (RR), systolic, diastolic, and mean arterial blood pressure (SAP, DAP, and MAP), end-tidal carbon dioxide (EtCO₂), and peripheral oxygen saturation (SpO₂) recorded five minutes before pneumoperitoneum (PREP), after abdominal insufflation (PP1), at 10 (PP2) and 20 (PP3) minutes post-insufflation, and 5 min after pneumoperitoneum interruption (POSTP). HR and RR were statistically significantly higher (p < 0.05) in the MK group compared to the MZ group at all time points of the study. EtCO₂ was significantly higher (p < 0.05) in the MZ group at PP2, PP3, and POSTP time points. The incidence of hypotension was significantly greater in the MZ group (45.5%) compared to the MK group (6.25%). Hypercapnia was observed in all baboons sedated with the MZ protocol compared to 12.5% of the MK group. As a result, the MK protocol provided greater cardiorespiratory stability during laparoscopic surgery. Full article

This study evaluated the effects of varying medetomidine doses on a tiletamine-zolazepam and tramadol anesthetic combination in dogs. The objective was to assess how medetomidine influences anesthesia depth, cardiovascular function, and recovery quality. Dogs were assigned to one of three treatment groups: tiletamine-zolazepam and tramadol without medetomidine (TZT), additional 10 µg/kg medetomidine (TZTM10), or additional 20 µg/kg medetomidine (TZTM20). Each dog received an intramuscular injection of 0.1 mL/kg of the designated solution. The formulation for TZT contained 25 mg/mL tiletamine and zolazepam and 40 mg/mL tramadol, while TZTM10 and TZTM20 received the same solution with additional medetomidine at 100 and 200 µg/mL, respectively. Onset time, anesthetic time, analgesic time, recovery quality, and physiological parameters, including heart rate, blood pressure, respiratory rate, oxygen saturation, and body temperature, were evaluated. Medetomidine extended analgesic time in a dose-dependent manner and improved recovery quality while maintaining stable respiratory function. While TZT provided adequate anesthesia for minor non-invasive procedures, the inclusion of medetomidine in TZTM resulted in enhanced anesthetic stability for simple surgical procedures such as gonadectomy. These findings suggest that TZTM20 is a viable anesthetic protocol, though careful patient monitoring remains essential due to its cardiovascular effects. Full article

Baboons’ management requires chemical restraint. Three intramuscular sedative protocols in captive hamadryas baboons (Papio hamadryas) undergoing health-check and male vasectomy were compared. Animals were assigned to TZD_G (n = 17; tiletamine/zolazepam 3 mg/kg + dexmedetomidine 20 μg/kg), KDM_G (n = 23; ketamine 6 mg/kg + dexmedetomidine 30 μg/kg + methadone 0.2 mg/kg), or MDM_G (n = 9; midazolam 2 mg/kg + dexmedetomidine 60 μg/kg + methadone 0.2 mg/kg). Propofol was titrated intravenously for anaesthetic induction and maintenance. Sedation time and quality and cardiopulmonary parameters were recorded. Atipamezole (TZD_G 0.2 mg/kg, KDM_G 0.3 mg/kg, MDM_G 0.6 mg/kg) and flumazenil (MDM_G 0.02 mg/kg) were administered intramuscularly post-procedure. Recovery time and quality were recorded. Data were reported as median (interquartile range) or regression coefficient (B). Sedation was deepest in TZD_G (20, 20–20; KDM_G 20, 19–20; MDM_G 19, 15–20; p = 0.017). MDM_G had a significantly higher heart rate (B = 10.27, p = 0.001), respiratory rate (B = 9.09, p < 0.001), and lower end-tidal carbon dioxide (B = −3.00, p = 0.03) than TZD_G, while KDM_G had a lower respiratory rate than TZD_G (B = −3.67, p = 0.02) and a higher temperature (B = 1.66 p = 0.001). TZD_G showed the longest recovery (minutes: 19, 11.5–30; KDM_G: 6, 4–12; MDM_G: 4, 2.5–5; p < 0.001), while MDM_G the best recovery (0, 0–0; TZD_G: 9, 6–12; KDM_G: 0, 0–6; p < 0.001). TZD produced deepest sedation but bad recovery; KDM offered optimal sedation and recovery, and cardiopulmonary stability; MDM provided lighter sedation and excellent recovery. Full article

Anaesthesia is sometimes required for the effective restraint of laboratory pigs for sample collection. Yet, anaesthesia can initiate a range of physiological disruptions that can increase variability in study data and lead to poorer animal welfare. Judicious use of anaesthesia can mitigate experimental, human safety, and animal welfare concerns, but it does not eliminate the potential for adverse effects. The use of reversal agents can shorten recovery time and reduce the physiological impacts of anaesthesia but can also cause additional side effects. We, therefore, trialled the use of low-dose atipamezole (0.12 mg/kg) for the antagonism of xylazine in laboratory pigs anaesthetised using a combination of xylazine and zolazepam/tiletamine. We measured time to recovery, selected clinical variables, recovery characteristics, and behaviours to investigate if a low dose of antagonist decreased recovery time and reduced the physiological impacts of anaesthesia whilst avoiding adverse negative side effects. We categorised side effects and behaviours as having either a low or high negative welfare impact based on the potential risk of injury and whether behaviours were displayed before or after return to consciousness. Collectively, our results indicated that while the use of low-dose atipamezole decreased recovery time and improved thermoregulation in most pigs, it introduced and exacerbated adverse side effects and behaviours that can lead to poorer welfare outcomes for laboratory pigs. Full article

The aim of this retrospective clinical study was to compare the combinations of ketamine/diazepam (KD group) and tiletamine/zolazepam (TZ group) for the induction of general anaesthesia in horses undergoing elective surgery. The data from the clinical and the anaesthetic records of 138 horses from 2021 to 2023 were evaluated, and the horses were divided in two groups: KD (n = 60) and TZ (n = 72). The horses were premedicated with romifidine and methadone IV; anaesthesia was induced with ketamine/diazepam for the KD group and tiletamine/zolazepam for the TZ group and was maintained with isoflurane and a constant rate infusion of romifidine. The data encompassed sex and neuter status, age, breed, weight, American Society of Anaesthesiologists physical status, type of surgical procedure performed under anaesthesia, induction time, induction score, surgery time, recovery time, and the recovery score using a descriptive scale. Baseline heart rate (HR), intraoperative HR, baseline respiratory rate (fR), intraoperative fR, mean arterial pressure (MAP), oxygen saturation (SpO₂), and fraction of expired isoflurane (F_E’Iso) were also recorded. The induction time was significantly longer (p = 0.004) in the TZ group (60 (40–120)) as compared to the KD group (50 (30–120)). Recovery time was also significantly longer (p ≤ 0.001) in the TZ group (46.5 (15–125)) as compared to the KD group (30 (5–105)). These findings suggested that, in adult horses undergoing elective surgery, TZ could be considered a valid alternative to KD for the induction of general anaesthesia. Additional experimental studies comparing the two induction regimens and their pharmacokinetic and pharmacodynamic characteristics are needed. Full article

This study aimed to evaluate dexmedetomidine as an alternative to xylazine in pigs. We compared TKD (0.05 mL/kg) to TKX (0.05 mL/kg) in 20 male pigs undergoing unilateral cryptorchid castration (short-term, 45-min) or bilateral cryptorchid castration (long-term, 90-min). We hypothesized that TKD would be comparable to TKX for both short-term and long-term anesthesia. Monitored parameters were classified into duration and physiological categories, including induction and recovery times, reflexes, heart rate (HR), respiratory rate (RR), arterial blood pressure, oxygen saturation (%SpO2), end-tidal carbon dioxide (ETCO2), and body temperature (TEMP). Isoflurane levels were also recorded, if used. Results showed no significant differences in duration parameters between TKD and TKX for either short-term or long-term anesthesia (induction: 1 min; recovery: 18–35 min). Physiological parameters were mostly similar between groups, although TKD caused slightly higher blood pressure during short-term anesthesia. Isoflurane levels (0.1–0.6%) were comparable between groups. Overall, the results suggest that TKD provides anesthesia comparable to TKX in pigs undergoing unilateral or bilateral cryptorchid surgery requiring short-term and long-term anesthesia. Full article

The surgical site infiltration of a local anesthetic is defined as the direct injection of a drug. This study aimed to compare the effects of surgical site infiltration with 4 mg kg⁻¹ lidocaine using a Comfort-in device and traditional syringe on oxidative status and intra- and postoperative pain in dogs undergoing regional mastectomy. Sixty adult female dogs divided into C (Comfort-in device), S (traditional syringe), and CTR (control) groups received 2 µg kg⁻¹ dexmedetomidine and 4 mg kg⁻¹ tramadol IM, 5 mg kg⁻¹ tiletamine/zolazepam IV, and isoflurane. The physiological and anesthesiological parameters were measured. The assessment of intra- and postoperative responses to the surgical stimulus was performed using a cumulative pain scale (CPS score of 0–4) and the Colorado Pain Scale (CSU-CAPS score of 0–4). The hematological and biochemical parameters and inflammatory oxidative status were measured. The CPS scores showed no significant differences between the C and S groups (p = 0.236), while the comparison between the CTR, C, and S groups, respectively, showed a significant difference (p < 0.001). The postoperative analgesia scores were significantly lower in the C group compared to those of the S and CTR groups (p < 0.001). In the C group, no subject received rescue analgesia during the intra- and postoperative periods. The level of oxidative inflammatory stress was lower in group C than those in S and CTR groups, and no side effects were observed in all the groups. Full article

Formosan serows are endemic to the mountainous regions of Taiwan. This crossover study aimed to assess and compare the anesthetic induction and recovery using either dexmedetomidine–tiletamine–zolazepam (DZ) or dexmedetomidine–ketamine (DK) by intramuscular injection from a blow-dart in a zoo environment. Ten anesthetic procedures were performed with five adult Formosan serows. Each participant was anesthetized with both combinations at least once with a minimal 12-month washout. The average dosages were 22.6 ± 8.3 µg/kg and 35.8 ± 2.5 µg/kg for dexmedetomidine and 185.6 ± 123.6 and 357.8 ± 25.2 µg/kg for atipamezole for the DZ and DK groups, respectively. The doses of tiletamine–zolazepam and ketamine were 2.1 ± 0.25 mg/kg and 3.6 ± 0.3 mg/kg, respectively, in the DZ and DK groups. All participants were induced within 10 min (median: 8 min for both groups), except one serow in the DK group with an induction time of 22 min. Serows in the DZ group had a lower respiratory rate (p = 0.016) and lower rectal temperature (p = 0.008) than those in the DK group. The quality of recovery was poor for DZ because of paddling, prolonged recovery, and ataxia after antagonism of dexmedetomidine with atipamezole. The induction of anesthesia with dexmedetomidine–tiletamine–zolazepam was uneventful and rapid. However, recovery from this combination was not smooth. Full article

This study was performed to evaluate the anesthetic protocol used in the high-quality, high-volume spay and neuter (HQHVSN) of free-roaming cats in Seoul, Korea from 2017 to 2022. The evaluation was performed on a total of 1261 free-roaming cats, with an average weight of 3.48 ± 1.04 kg. The anesthetic combination tiletamine-zolazepam, ketamine, and xylazine (ZKX) was injected intramuscularly. The actual drug doses administered were tiletamine-zolazepam 5.52 ± 1.70 mg/kg, ketamine 8.94 ± 3.60 mg/kg, and xylazine 1.11 ± 0.34 mg/kg. Additional doses were required in 275 cats out of a total of 1261 (21.8%). Following anesthesia and surgery, 1257 cats (99.7%) were returned to their original locations. Four cats (0.3%) died postoperatively. The mean duration of anesthesia (from ZKX combination to yohimbine administration) was 26 ± 22 min for males and 55 ± 36 min for females, while the time from yohimbine administration to the recovery was 31 ± 22 min for males and 20 ± 17 min for females. The use of ZKX for HQHVSN of free-roaming cats is inexpensive, provides predictable results, can be administered quickly and easily in a small volume, and is associated with a low mortality rate during the first 72 h post-surgery. Full article

The aim of the study was to compare the analgesic efficacy of tramadol and lidocaine for local anesthesia during umbilical hernia repair in swine. The study was performed on 66 large white crossbred swine. The swine received a mixture of tiletamine/zolazepam at 5 mg/kg and romifidine at 80 µg/kg, administered intramuscularly. Then, they were divided into three groups (n = 22) that received different treatments with lidocaine at 4 mg/kg and tramadol at 4 mg/kg. The LL group received lidocaine both by infiltration of the surgical planes and intraperitoneally. The LT group received lidocaine by infiltration of the surgical planes and tramadol intraperitoneally. The TT group received tramadol both by infiltration of the surgical planes and intraperitoneally. In all groups, the infiltration of the surgical planes into the umbilical region involved both the skin and muscle planes. Heart rate, noninvasive arterial blood pressure, and respiratory frequency were recorded during surgery. The response to the surgical stimulus was evaluated using a cumulative pain scale (the cut-off point for rescue analgesia was set to 10). Postoperative pain was assessed using the UNESP-Botucatu pig composite acute pain scale (the cut-off point was set to 4). The trend of physiological variables was adequate for patients under anesthesia. No subject required intraoperative and postoperative rescue analgesia. Tramadol could therefore be used for pain management in livestock. Full article

The study aims to describe the anesthetic and airway management of baboons (Papio hamadryas) undergoing laparoscopic salpingectomy with a laryngeal mask airway (LMA) device. Eleven baboons received tiletamine-zolazepam and medetomidine; anesthesia was induced with propofol. An LMA was positioned for oxygen and isoflurane administration in spontaneous respiration. Heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR), end tidal carbon dioxide (EtCO₂), minute volume (MV), and peripheral hemoglobin oxygen saturation (SpO₂) were recorded before (PREPP) and immediately after abdomen insufflation (PP1), at 10 (PP2), 20 (PP3), and 30 (PP4) minutes during pneumoperitoneum, and after (POSTPP) pneumoperitoneum. The respiratory rate was significantly higher at all times compared to PREPP. The end tidal carbon dioxide concentration was significantly higher at PP2, PP3, PP4, and POSTPP, compared to the previous times. The higher values for RR and EtCO₂ were registered at PP4: 22.7 (95% CI 17.6–27.8) breaths/min and 57.9 (95% CI 51.9–63.8) mmHg, respectively. The minute volume was significantly higher at PP4 and POSTPP compared to the other times. The higher value for MV was registered at POSTPP (269.1 (95% CI 206.1–331.8) mL/kg/min). This protocol is suitable for baboons undergoing laparoscopic salpingectomy. The LMA was easy to insert and allowed for good ventilation, gas exchange, and delivery of the anesthetic in spontaneous breathing baboons. Full article

Marmosets’ small body size makes anesthesia challenging. Ideally, small volumes of drugs should be administered intramuscularly (i.m.). In addition, dose-dependent sedation and anesthesia are desirable properties for sedatives and anesthetics in marmosets. Telazol^® (tiletamine and zolazepam) is highly concentrated, allowing the use of small injection volumes and dose-dependent sedation and anesthesia. A randomized, blinded study with crossover design in ten healthy adult common marmosets (Callithrix jacchus) was performed to evaluate the anesthetic and cardiorespiratory effects of three doses of i.m. Telazol^® (respectively, 5, 10, and 15 mg/kg). Depth of anesthesia, cardiorespiratory effects, and induction, immobilization, and recovery times were determined. A significant difference was observed in immobilization time between 5 and 15 mg/kg of Telazol^®. In addition, 15 mg/kg of Telazol^® resulted in increased recovery times compared to 5 mg/kg. The cardiorespiratory effects during the first 45 min of immobilization were within clinically acceptable limits. The pedal withdrawal reflex was the best indicator of the anesthetic depth. Full article

CO₂ inhalation is currently the most common method of euthanasia for laboratory rats and mice, and it is often used for further terminal blood sampling for clinical biochemical assays. Lately, this method has been criticized due to animal welfare issues associated with some processes that develop after CO₂ inhalation. The stress reaction and the value of the clinical laboratory parameters significantly depend on the used anesthetics, method, and the site of blood sampling. Especially in small rodents, an acute terminal state followed by a cascade of metabolic reactions that can affect the studied biochemical profile may develop and cause unnecessary suffering of animals. The aim of this study was to compare the stability of biochemical parameters of outbred Sprague Dawley rats and CD-1 mice serum collected after CO₂ inhalation or the intramuscular injection of tiletamine–zolazepam–xylazine (TZX). The serum content of total protein and albumin, cholesterol, triglycerides, aspartate aminotransferase (AST), alanine aminotr ansferase (ALT), alkaline phosphatase (ALP), total bilirubin, and creatinine was decreased by the injection of TZX in comparison with CO₂ inhalation. In addition, the levels of calcium, phosphates, chlorides and potassium were lowered by TZX vs. CO₂ administration, while the level of sodium increased. Finally, the level of the majority of serum clinical biochemical parameters in rats and mice tend to be overestimated after CO₂ inhalation, which may lead to masking the possible effect of anti-inflammatory drugs in animal tests. Injection anesthesia for small rodents with TZX is a more feasible method for terminal blood sampling, which also reduces the suffering of animals. Full article