Zolazepam Hydrochloride Research Articles

Pulsed-field ablation: an alternative ablative method for gastric electrophysiological intervention.

Pulsed-field ablation (PFA) is an emerging ablative technology that has been used successfully to eliminate cardiac arrhythmias. As a nonthermal technique, it has significant benefits over traditional radiofrequency ablation with improved target tissue specificity and reduced risk of adverse events during cardiac applications. We investigated whether PFA is safe for use in the stomach and whether it could modulate gastric slow waves. Female weaner pigs were fasted overnight before anesthesia was induced using tiletamine hydrochloride (50 mg·mL-1) and zolazepam hydrochloride (50 mg·mL-1) and maintained with propofol (Diprivan 2%, 0.2-0.4 mg·kg-1·min-1). Pulsed-field ablation was performed on their gastric serosa in vivo. Adjacent point lesions (n = 2-4) were used to create a linear injury using bipolar pulsed-field ablation consisting of 40 pulses (10 Hz frequency, 0.1 ms pulse width, 1,000 V amplitude). High-resolution electrical mapping defined baseline and postablation gastric slow-wave patterns. A validated five-point scale was used to evaluate tissue damage in hematoxylin and eosin-stained images. Results indicated that PFA successfully induced complete conduction blocks in all cases, with lesions through the entire thickness of the gastric muscle layers. Consistent postablation slow-wave patterns emerged immediately following ablation and persisted over the study period. Pulsed-field ablation induces rapid conduction blocks as a tool to modulate slow-wave patterns, indicating it may be suitable as an alternative to radiofrequency ablation.NEW & NOTEWORTHY Results show that pulsed-field ablation can serve as a gastric slow-wave intervention by preventing slow-wave propagation across the lesion site. Stable conduction blocks were established immediately following energy delivery, faster than previous examples of radiofrequency gastric ablation. Pulsed-field ablation may be an alternative for gastric slow-wave intervention, and further functional and posthealing studies are now warranted.

Наркотизация в доклинических исследованиях. Сообщение 2: карликовые свиньи

Anesthesia of dwarf pigs, depending on the expected severity of the procedures, is an urgent issue in preclinical studies. The effect of different doses and combinations of drugs was studied: Xyla® (xylazine hydrochloride, Estonia) and Zoletil® (tiletamine hydrochloride and zolazepam hydrochloride, France); Zoletil® and Propofol® (propofol, Germany); Meditin® (medetomidine hydrochloride, Russian Federation) and Isoflurane® (India); Xyla® (Estonia) and Isoflurane®, Propofol® (Germany) and Isoflurane® (India); Meditin® (Russian Federation) on the duration of anesthesia, glucose levels and physiological parameters of dwarf pigs. It was found that for procedures characterized by a mild degree of duration (up to 20 minutes), a combination of xylazine hydrochloride (0.1 mg/kg) in combination with tiletamine hydrochloride and zolazepam hydrochloride (2 mg/kg) should be used. For moderate severity procedures, combinations of xylazine hydrochloride (1 mg/kg) and tiletamine hydrochloride with zolazepam hydrochloride (6 mg/kg) can be used, if necessary, anesthetic support for about 1 hour; if 40-minute anesthesia is sufficient, medetomidine hydrochloride (100 mcg) can be used + isoflurane (4.5:1.0 vol.%); xylazine hydrochloride (5 mg/kg) + isoflurane (4.5:1.0 vol.%); with 30-minute anesthesia — xylazine hydrochloride (5 mg/kg) + isoflurane (4.5:1.0 vol.%). In the case of anesthetic support for procedures characterized as severe or “without leaving anesthesia”, a combination of xylazine hydrochloride (22 mg/kg) and tiletamine hydrochloride in combination with zolazepam hydrochloride (8.8 mg/kg), the duration of anesthesia up to 84 minutes; and medetomidine hydrochloride (100 mcg) are applicable + isoflurane (4.5:1.5 vol.%), duration of action up to 40 minutes; xylazine hydrochloride (8 mg/kg) + isoflurane (4.5:1.5 vol.%). The use of a combination of tiletamine hydrochloride and zolazepam hydrochloride together with propofol, propofol and isoflurane is not recommended or requires additional study. A combination of medetomidine hydrochloride (100 mcg) and isoflurane (4.5:1.0 vol.%) leads to an increase in glucose levels in male dwarf pigs. In the case of a combination of xylazine hydrochloride (8 mg/kg) and isoflurane (4.5:1.5 vol.%) glucose levels increase in both males and females. Xylazine hydrochloride in combination with tiletamine hydrochloride and zolazepam hydrochloride, depending on the dose, leads to a decrease in saturation, an increase in the P and PQ intervals (P wave and PQ interval) and, regardless of the dose, increases the frequency of respiratory movements. Medetomidine hydrochloride and isoflurane lead to an increase in blood pressure and an increase in the P wave and the PQ interval with a moderate degree of anesthesia. The use of a combination of xylazine hydrochloride and isoflurane with moderate and deep anesthesia leads to an increase in PQ.

A Novel and Simple Method for Tracheal Intubation in a Swine Model: Preparing for the Era of Xenotransplantation.

Organ transplant in humans is an established therapy for a variety of end-stage organ diseases. However, due to organ shortages and lack of donors, the need for xenotransplant has gradually increased. Xenotransplantation has great potential to solve many of the problems facing organ transplantation. Pigs are being developed as xenogeneic organ donors for use in humans. In this study, we propose a novel and simple method for tracheal intubation in a swine model using neuromuscular blocking agents and laryngeal mask airway. Eight Yorkshire pigs were used for the 2 separate experiments, which were conducted 1 week apart. In the first experiment, an anesthesiologist with no previous comparable experience performed endotracheal intubation of pigs. One week later, using the same pig, a second experiment was performed by an experienced anesthesiologist. Anesthesia was induced with intramuscular injection of a mixture of 1 mg/kg xylazine (Rompun, Bayer Korea Ltd., Seoul, Korea) and 7 mg/kg Zoletil (a mixture of tiletamine hydrochloride and zolazepam hydro-chloride, Virbac Laboratory, Carros, France). The laryngeal mask was then placed, and 0.15 mg/kg vecuronium bromide was injected intravenously. Tracheal intubation was attempted after mask removal. The duration and number of intubation attempts were recorded, and the degree of intubation difficulty was scored. In all cases, the laryngeal mask was easily inserted, and endotracheal intubation was successfully completed. Oxygen saturation did not fall below 95%, and there were no hypoxemia episodes. Degree of intubation difficulty and duration were not significantly different between the 2 anesthesiologists. Tracheal intubation in our swine model was successfully performed using neuromuscular blocking agents and laryngeal masks without resulting in hypoxemia, with even anesthesiologists who are unfamiliar with endotracheal intubation of pigs easily able to do so using our protocol. Therefore, our protocol will enable all investigators to perform successful tracheal intubation in swine models.

Effect of dexmedetomidine hydrochloride on tiletamine hydrochloride-zolazepam hydrochloride anesthesia in alpacas.

OBJECTIVE To evaluate the effect of IM administration of a tiletamine hydrochloride-zolazepam hydrochloride (TZ) combination with either dexmedetomidine hydrochloride or saline (0.9% NaCl) solution (SS) on the motor response to claw clamping, selected cardiorespiratory variables, and quality of recovery from anesthesia in alpacas. ANIMALS 5 adult sexually intact male alpacas. PROCEDURES Each alpaca was given the TZ combination (2 mg/kg) with dexmedetomidine (5 [D5], 10 [D10], 15 [D15], or 20 [D20] µg/kg) or SS IM at 1-week intervals (5 experiments); motor response to claw clamping was assessed, and characteristics of anesthesia, recovery from anesthesia, and selected cardiorespiratory variables were recorded. RESULTS Mean ± SEM duration of lack of motor response to claw clamping was longest when alpacas received treatments D15 (30.9 ± 5.9 minutes) and D20 (40.8 ± 5.9 minutes). Duration of lateral recumbency was significantly longer with dexmedetomidine administration. The longest time (81.3 ± 10.4 minutes) to standing was observed when alpacas received treatment D20. Following treatment SS, 4 alpacas moved in response to claw clamping at the 5-minute time point. Heart rate decreased from pretreatment values in all alpacas when dexmedetomidine was administered. Treatments D10, D15, and D20 decreased Pao2, compared with treatment SS, during the first 15 minutes. During recovery, muscle stiffness and multiple efforts to regain a sternal position were observed in 3 SS-treated and 1 D5-treated alpacas; all other recoveries were graded as excellent. CONCLUSIONS AND CLINICAL RELEVANCE In TZ-anesthetized alpacas, dexmedetomidine (10, 15, and 20 µg/kg) administered IM increased the duration of lack of motor response to claw clamping, compared with the effect of SS.

Establishment of a Rabbit Model of Obstructive Sleep Apnea by Paralyzing the Genioglossus

This study presents an innovative method for developing a neuromuscular model of obstructive sleep apnea (OSA). To establish a new OSA animal model simulating real upper airway conditions during sleep. In vivo animal study at an academic tertiary referral center. A total of 27 New Zealand white male rabbits were used. Sleep was induced by intramuscular injection of 0.3 mL/kg of tiletamine hydrochloride plus zolazepam hydrochloride and 0.2 mL/kg of xylazine. Upper airway obstruction was induced by injecting botulinum toxin type A (2.5 U in 8 rabbits, 5.0 U in 10 rabbits, and 7.5 U in 1 rabbit) into the genioglossus. Eight rabbits were injected with normal saline as a control. Drug-induced sleep was evaluated using a portable polysomnography device for electroencephalography, electrooculography, chin electromyography, nasal airflow, breathing efforts, and pulse oxymetry. Respiratory events (apneas or hypopneas) during sleep were evaluated using a sleep-screening tool. All the rabbits showed no apneas or hypopneas before injection of botulinum toxin type A. In the control rabbits injected with normal saline, apneas or hypopneas were not found. The respiratory events were observed in 5 of 8 rabbits injected with 2.5 U of botulinum toxin type A, whereas they were observed in 7 of 10 rabbits injected with 5.0 U of botulinum toxin type A. The median (interquartile range) apnea hypopnea index was 9.6 (5.3-14.8) per hour and 45.6 (21.5-70.5) per hour in the rabbits injected with 2.5 U and 5.0 U of botulinum toxin type A, respectively (P = .03). An animal model of OSA could be developed by paralyzing the genioglossus in rabbits. This model may contribute to identifying the pathogenesis of upper airway obstruction in OSA and to developing new diagnostic or treatment devices targeting specific obstruction sites.

Effects of chemical immobilization on the movement rates of free-ranging polar bears

The capture and handling of free-ranging animals is an important tool for wildlife research, conservation, and management. However, live capture may expose individual animals to risk of injury, impairment, or mortality. The polar bear (Ursus maritimus) is a species of conservation concern throughout its range and physical mark– recapture techniques have formed the basis of polar bear research and harvest management for decades. We examined movement patterns of polar bears postcapture to measure their recovery from chemical immobilization and determine whether captured bears experienced prolonged effects that would affect individual fitness. Adult female (n ¼ 61) and juvenile (n ¼ 13) polar bears in 3 Canadian subpopulations were captured during the course of other studies using a combination of tiletamine hydrochloride and zolazepam hydrochloride delivered via remote injection from a helicopter. Bears were fitted with satellite-linked global positioning system collars and we used 3 individual-based metrics to assess their recovery from immobilization: time to move 50 m; time to move 100 m; and time to reach a baseline movement rate threshold (km/day) derived from each individual’s movements in a fully recovered state (i.e., 30–60 days postcapture). There were no differences in recovery rate metrics across years, age classes, or between females with cubs of different ages. When compared across subpopulations, only the time to move 50 m differed, being shortest in the southern Beaufort Sea. Bears captured on land during the ice-free period in western Hudson Bay and Foxe Basin were more variable in their response to capture than were those handled on the sea ice of the Beaufort Sea, but in all 3 areas, bears showed gradual increases in movement rates. Movement rates indicative of recovery were often reached 48 h after capture and 51 (69%) of 74 bears appeared to be fully recovered in � 3 days. Consistent with preliminary work on chemical immobilization of polar bears, there was no relationship between drug dose and rate of recovery. Our results indicated that polar bears captured in different locations, seasons, and life-history stages recovered predictably from chemical immobilization in a time frame that is unlikely to affect individual fitness.

Immobilization of Japanese Black Bears (Ursus thibetanus japonicus) with Tiletamine Hydrochloride and Zolazepam Hydrochloride

The effect of anesthetizing with a 1:1 combination of tiletamine hydrochloride and zolazepam hydrochloride (TZ) was evaluated in 75 Japanese black bears. TZ was administered to 43 captive and 11 wild, 8 captives and 13 hibernating captive bears at the doses of approximately 9.0 mg/kg (usual dosage), 18.0 mg/kg (high dosage) and 5.0 mg/kg (low dosage), respectively. Sufficient anesthetic effects were achieved in all bears, and rectal temperatures, heart rates and respiratory rates did not change significantly during an hour handling. Complete blood cell examinations showed no abnormal data. A combination of TZ would be an efficient and safe drug for chemical immobilization of Japanese black bears.

Chemical immobilization of free-ranging dhole (Cuon alpinus), binturong (Arctictis binturong), and yellow-throated marten (Martes flavigula) in Thailand

No published information exists on the chemical immobilization of free-ranging dholes (Cuon alpinus), binturongs (Arctictis binturong), or yellow-throated martens (Martes flavigula). We chemically immobilized these species in Thailand using a mixture of ketamine hydrochloride with xylazine hydrochloride (KH–XH) and tiletamine hydrochloride with zolazepam hydrochloride (TH–ZH). Mean (±SD) dose of KH–XH was 18.1±5.3 and 0.9±0.1 mg/kg for dholes (n=2), 19.7±4.1 and 1.3±0.4 mg/kg for binturongs (n=8), and 28.7±3.3 and 1.1±0.1 mg/kg for yellow-throated martens (n=5), respectively. Mean dose of TH–ZH was 4.1±0.1 mg/kg for dhole (n=2). Induction time, duration of anesthesia, and recovery time were satisfactory for standard field research procedures including radio-collaring, although the effects on yellow-throated martens and binturongs were more variable. Respiration and muscle rigidity were monitored during sedation with no observed adverse physiological effects. Individuals were released after full recovery and monitored via radio telemetry for 4–23 months with no observed detrimental effects due to chemical immobilization. We conclude that KH–XH and TH–ZH are safe and effective immobilization agents for these carnivores; however, we suggest testing different KH–XH ratios and dosages, and other immobilizing agents for these species.

IMMOBILIZATION OF FREE-RANGING MANED WOLF (CHRYSOCYON BRACHYURUS) WITH TILETAMINE AND ZOLAZEPAM IN CENTRAL BRAZIL

A tiletamine hydrochloride-zolazepam hydrochloride combination was used successfully to immobilize 27 free-ranging maned wolves (Chrysocyon brachyurus) at a mean dose of 2.77+/-0.56 (mean+/-SD) mg/kg. The induction time ranged from 3-15 min. Animals remained immobilized for periods of 48.56 +/-12.65 min. Compulsive licking, excessive salivation, muscle twitching, muscle tremors, tachypnea, and bradycardia were observed associated with the induction of the anesthesia in 13 of 27 maned wolves. Muscle twitching, pedal withdrawal reflex, muscle tremors, and ataxia were observed during recovery in three (11%) maned wolves. There were no significant differences in heart rates (P = 0.44), respiratory rates (P = 0.82), and rectal temperatures (P = 0.54) recorded at 5, 15, and 25 min after induction at these dosages. The tiletamine hydrochloride-zolazepam hydrochloride combination was shown to be an effective and safe immobilizing agent for free-ranging maned wolves.

Comparative immobilization of wild felids in Thailand.

We immobilized individuals of four free-ranging felid species, leopard cat (Prionailurus bengalensis), clouded leopard (Neofelis nebulosa), Asiatic golden cat (Catopuma temminckii), and marbled cat (Pardofelis marmorata) with ketamine hydrochloride and xylazine hydrochloride (KH-XH) and with tiletamine hydrochloride and zolazepam hydrochloride (TH-ZH) between March 1998 and July 2002. Mean (+/-SD) dose of KH and XH was 26.51+/-5.71 mg/kg and 1.89+/-0.43 mg/kg, respectively (n=25), and mean dose of TH-ZH was 11.61+/-3.39 mg/kg (n=28). Dose was significantly correlated with induction time (P<0.001) and duration of anesthesia (P<0.05), but not with recovery time. There were significant differences between the drug combinations in time to induction (P<0.03) and time to anesthesia (P<0.01); recovery times were not significantly different. We conclude that immobilization of these felids with TH-ZH and KH-XH is effective and safe, but TH-ZH is preferred because of the smaller volume of drug necessary for sedation, faster time to induction, and absence of prolonged muscle rigidity during anesthesia.

Pharmacokinetics and tissue residues of Telazol in free-ranging polar bears.

A pharmacokinetic and tissue residue study was conducted to assess the risks associated with human consumption of polar bears in arctic Canada that have been exposed to the immobilizing drug Telazol, a mixture of tiletamine hydrochloride and zolazepam hydrochloride. Twenty-two bears were remotely injected with about 10 mg/kg of Telazol. Following immobilization, serum samples were collected serially at regular intervals until the bears awakened. Sixteen of the bears were relocated and killed under permit by local hunters at various times from 0.5 to 11 days after dosing. Serum, kidney, muscle and adipose tissue samples were collected immediately after death. All samples were stored at -70 C until analysis by HPLC. The concentration-time data of tiletamine and zolazepam in serum during the immobilization period were fitted to curves by computer and the pharmacokinetic parameters assessed. In addition, the serum and tissue samples collected at the time of death were analyzed for both parent drugs, for one metabolite of tiletamine (CI-398), and for three metabolites of zolazepam (metabolites 1, 2 and 4). A one-compartment model with first-order absorption and elimination best fit the time-series data for the drugs in serum during the immobilization period. This model gave half-lives (mean +/- SE) for tiletamine and zolazepam of 1.8+/-0.2 h and 1.2+/-0.08 h, respectively, clearance values of 2.1+/-0.3 l x h(-1) x kg(-1) and 1.1+/-0.1 l x h(-1) x kg(-1), and volumes of distribution of 5.2+/-0.6 l/kg and 1.8+/-0.2 l/kg. The concentrations of both drugs and their metabolites declined rapidly to trace levels by 24 h post-dosing, although extremely low concentrations of some metabolites were encountered sporadically over the entire sampling period. In particular, zolazepam metabolite 2, remained detectable in fat and muscle tissue at the end of the study, 11 days after dosing. It was concluded that during immobilization, both tiletamine and zolazepam levels decline rapidly in a monoexponential fashion, and their pharmacokinetic parameters in polar bears are similar to those observed in other species. Tissue levels of the drugs and their metabolites declined sufficiently rapidly that individuals eating meat from exposed bears would be unlikely to experience pharmacological effects from the drugs. Nevertheless, slight exposure to the drugs and/or their metabolites might be possible for an indeterminate time after dosing.

Cloridrato de tiletamina associado com cloridrato de zolazepam na tranqüilização e anestesia de calitriquídeos (Mammalia, Primates)

Utilizou-se a associação de cloridrato de tiletamina (125mg) e cloridrato de zolazepam (125mg) diluídos em água destilada (10ml) como tranqüilizante e anestésico em 38 animais pertencentes às espécies Saguinus imperator imperator (N= 21), Saguinus fuscicollis weddeli (N= 15) e Cebuella pygmea (N=2). Indivíduos de ambos os sexos, com pesos entre 130 e 520g, receberam doses de 0,02ml (1,11mg/kg) a 0,15ml (8,33mg/kg) pela via intramuscular. Na maioria dos casos ocorreu anestesia. Os animais foram libertados no mesmo dia da captura, após recuperação pós-anestésica. Não ocorreu efeito colateral aparente sobre os fetos de duas fêmeas gestantes. Apesar da morte de um animal jovem, os resultados foram considerados satisfatórios na tranqüilização e anestesia de calitriquídeos.

Behavioural Responses of Agile Wallabies (Macropus agilis) to Darting and lmmobilisation with Tiletamine Hydrochloride and Zolazepam Hydrochloride

A total of 28 free-ranging agile wallabies (Macropus agilis) was immobilised with a combination of tiletamine hydrochloride and zolazepam hydrochloride. The drug was administered by projectile syringe fired from a gas-powered pistol. A dose of approximately 10 mg per kg body mass produced ataxia in 3.8 ± 0.4 min (mean ± s.e.), initial recumbency in 4.9 ± 0.5 min, and lateral recumbency in 7.9 ± 0.7 min after dart impact. Wallabies were calm throughout handling, showed good muscle relaxation and started to regain consciousness after 53 ± 3 min. Recovery of mobility took more than 240 min and appeared uneventful. Wallabies moved 41 ± 5 m after dart impact, after which they either groomed or fed until the drug took effect. Five wallabies sought shelter in nearby forest after darting and these were found 11 ± 3 m inside the forest boundary.

Field immobilization of Ethiopian wolves (Canis simensis).

Telazol (tiletamine hydrochloride and zolazepam hydrochloride combination) and a combination of ketamine hydrochloride and acepromazine were used to immobilize wild Ethiopian wolves (Canis simensis) in Ethiopia from 1988 to 1992. Telazol doses of 2.1 to 6.5 mg/kg resulted in a mean (+/- SD) induction time of 2.3 +/- 0.9 min and a mean (+/- SD) immobilization time of 82.2 +/- 28.6 min. Induction time did not differ by dose, wolf weight, or age, but was significantly longer for females. Immobilization time differed with dose, but not by wolf weight, age, or sex. Total recovery times ranged from 50 to 158 min. There were no apparent side effects on immobilized animals. Wolves immobilized using a combination of ketamine hydrochloride and acetylpromazine had longer induction time (3.0 +/- 0.8 min) and recovery time (114.7 +/- 29.2 min). Telazol is an effective and safe agent for immobilizing Ethiopian wolves and is preferred to ketamine/acetylpromazine.

Evaluation of use of tiletamine/zolazepam for anesthesia of bullfrogs and leopard frogs

Summary Use of tiletamine hydrochloride and zolazepam hydrochloride (1:1 fixed ratio combination) as an anesthetic agent in 2 anuran species was studied. A dosage of 5 mg/kg of body weight, administered im, resulted in variable weak tranquilization. Intramuscular administration at dosages of 10 and 20 mg/kg induced variable states of tranquilization or anesthesia in leopard frogs (Rana pipiens) and bullfrogs (R catesbeiana). The dosages of 50 mg/kg induced anesthesia with greater consistency than lower dosages in bullfrogs, but resulted in mortalities. The same dosage was uniformly fatal in leopard frogs. Neither gross nor histologic lesions were identified in the frogs that died. Depth and duration of anesthesia was dosage related. At the 20 and 50 mg/kg dosages, leopard frogs attained a greater depth of anesthesia and remained anesthetized for a significantly greater duration than did bullfrogs; however, at the 5 and 10 mg/kg dosages, bullfrogs developed greater tranquilization for longer periods than did leopard frogs. Results of this study revealed profound intraspecies variation in depth and duration of effect of tiletamine/zolazepam; therefore, the drug does not appear to be a suitable injectable anesthetic in anurans.

The use of tiletamine hydrochloride and zolazepam hydrochloride for sedation of the mountain brushtail possun Trichosurus caninus Ogilby (Phalangeridae: Marsupialia)

A combination of tiletamine hydrochloride and zolazepam hydrochloride in a 1:1 ration by weight was used successfully to sedate mountain brushtail possums, Trichosurus caninus, in the field. A standard total dose of 50 to 60 mg provided adequate sedation for the completion of a range of handling procedures. We describe the induction time, dose rate and side-effects associated with the use of tiletamine and zolazepam in T caninus.

Immobilization of free-ranging red foxes (Vulpes vulpes) with tiletamine hydrochloride and zolazepam hydrochloride.

We evaluated Zoletil on free-ranging red foxes (Vulpes vulpes) in Spain. Twenty-two pup and 49 adult wild-caught red foxes (Vulpes vulpes) were immobilized with a combination of tiletamine hydrochloride and zolazepam hydrochloride in a 1:1 proportion (Zoletil). Mean (+/- SE) Zoletil doses were 10.57 (+/- 0.41) mg/kg (range = 7.58-15.39 mg/kg, n = 22) for pups and 10.51 (+/- 0.33) mg/kg (range = 5.88-16.67 mg/kg, n = 45) for adults. Mean induction and first recovery times for pups were 2.3 (+/- 0.2) minutes (range = 1 to 5 minutes) and 35.5 (+/- 3.28) minutes (range = 18 to 78 minutes), respectively. Mean induction and first recovery times for adults were 3.7 (+/- 0.21) minutes (range = 2 to 8 minutes) and 35.4 (+/- 2.22) minutes (range = 13 to 90 minutes), respectively. We recommend Zoletil doses of 10 mg/kg for red foxes. For wild adult red foxes of unknown weight, an initial dose of 60 to 70 mg Zoletil should be administered. This dose should allow about 40 minutes of handling time.

Immobilization of porcupines with tiletamine hydrochloride and zolazepam hydrochloride (Telazol).

Immobilization of North American porcupines (Erethizon dorsatum) with tiletamine hydrochloride (HCl) and zolazepam HCl (Telazol) was evaluated in central Massachusetts (USA) during 1991 and 1992. Doses between 9 and 11 mg/kg resulted in a mean (+/- SD) induction time of 3.2 +/- 1.3 min and a mean (+/- SD) immobilization time of 44.2 +/- 19.5 min. Induction time did not differ by dose, sex, capture method, or porcupine weight. Immobilization time differed by dose and porcupine weight but not by sex or capture method. Tiletamine HCl and zolazepam HCl seems to be an effective combination of drugs for immobilizing porcupines as long as sufficient time is allowed for recovery.

Field Application of Telazol® (Tiletamine Hydrochloride and Zolazepam Hydrochloride) to Immobilize Wild Red Howler Monkeys (Alouatta seniculus) in Venezuela

Telazol (TEL) (tiletamine hydrochloride and zolazepam hydrochloride combination) was used to immobilize 50 wild red howler monkeys (Alouatta seniculus) in Venezuela between October 1989 and February 1991. The mean (+/- SD) dosages of TEL used for adult males and adult females were 22.4 (+/- 7.3) mg/kg and 22.5 (+/- 5.0) mg/kg, respectively. Juveniles of both sexes received a mean dose of 30.5 (+/- 5.6) mg/kg. The induction time for TEL ranged from 1 to 6.2 min. Thirteen animals were given an additional dosage of ketamine hydrochloride manually when they recovered from the first injection of TEL. Total recovery times ranged from 39 to 308 min. There were no apparent side effects to the fetuses of two pregnant females.

Chemical restraint of Weddell seals (Leptonychotes weddellii) with a combination of tiletamine and zolazepam.

A 1:1 combination by weight of tiletamine hydrochloride and zolazepam hydrochloride was administered to 30 adult Weddell seals (Leptonychotes weddellii) in doses varying from 100 to 300 mg. Full immobilization was achieved in 16 seals, moderate sedation in seven and light sedation in seven. Three animals died; two were fully immobilized and one was moderately sedated prior to death. The drug combination was considered satisfactory, although its usefulness was limited by the lack of chemical antagonists when complications were encountered in immobilized animals.