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The field of lizard sedation, anesthesia, and locoregional anesthesia is advancing with new drug protocols being evaluated, and new locoregional techniques being developed and evaluated. Inducing and maintaining effective and safe chemical restraint in lizards can be challenging, particularly in systemically diseased individuals. Understanding the anatomic and physiologic adaptations of lizards, using reversible or partially reversible injectable protocols, and using locoregional anesthesia may increase the quality of chemical restraint, facilitate faster recoveries, and limit anesthesia-related morbidity and mortality., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: To assess the success rate, onset, duration and extent of motor/sensory block following neuraxial injection of two dosages of bupivacaine in bearded dragons (Pogona vitticeps)., Study Design: Prospective, randomized, blinded, crossover experimental study., Animals: A total of 10 adult bearded dragons (0.3 ± 0.1 kg)., Methods: After sedation with alfaxalone (15 mg kg -1 subcutaneously), neuraxial injections were performed with 1 or 2 mg kg -1 bupivacaine hydrochloride (0.5%, treatments BUP-1 and BUP-2, respectively) in a randomized treatment sequence with a 7 day washout period. If the initial bupivacaine injection was not successful within 10 minutes, a second injection was performed at the same dose. Mechanical stimulation of limbs, 25%, 50%, 75% of the trunk's length and cloacal tone were assessed., Results: Success rate following the first neuraxial injection was 95%, which increased to 100% after the second injection. Motor/sensory block were noted by 5 minutes after the injection of bupivacaine at either dose. BUP-2 was associated with more cranial spread. The median (range) duration of cloacal tone loss was longer following treatment BUP-2 [120 (75-225) minutes] than followed treatment BUP-1 [83 (25-135) minutes; p = 0.03]. Duration of pelvic limb motor block was comparable between both doses, lasting a median of 68 minutes in both treatments (p = 0.94). There was a transient, not clinically relevant increase from baseline in heart rate in treatment BUP-1 only. No significant difference from baseline in respiratory rate was noted in either treatment; however, two animals in treatment BUP-2 became apneic (10-20 minutes)., Conclusions and Clinical Relevance: Bupivacaine (1 mg kg -1 ) is recommended for neuraxial anesthesia in bearded dragons. In treatment BUP-2, extensive cranial spread resulted in apnea and motor block of the thoracic limb in several animals; therefore this dose is not recommended., (Copyright © 2021 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

The use of procedural sedation in birds has become a routine practice in veterinary medicine during the past 10 years, with a corresponding increase in avian sedation research. Sedation is most often used in a clinical setting for birds to facilitate examination and/or diagnostic sample collection, splint application, grooming, and minor surgical procedures. Sedation provides several benefits over manual restraint or general anesthesia when performing clinical procedures. This review provides an overview of current studies on avian sedation and discusses common indications, protocols, and adverse effects of sedation in avian patients.

In biomedical research, rabbits are commonly sedated to facilitate a variety of procedures. Developing a sedation assessment scale enables standardization of levels of sedation and comparisons of sedation protocols, and may help in predicting sedation level requirements for different procedures. The goal of this study was to develop a rabbit sedation assessment scale using a psychometric approach. We hypothesized that the sedation scale would have construct validity, good internal consistency, and reliability. In a prospective, randomized, blinded study design, 15 (8 females, 7 males) healthy 1-y-old New Zealand white rabbits received 3 intramuscular treatments: midazolam (0.5 mg/kg; n = 6); midazolam (1.5 mg/kg)-ketamine (5 mg/kg; n = 7); and alfaxalone (4 mg/kg)-dexmedetomidine (0.1 mg/kg)-midazolam (0.2 mg/kg; n = 3). One rabbit received 2 treatments. A sedation scale was developed by using psychometric methods, with assessment performed by 6 independent raters who were blind to treatment. Final sedation scale items included posture, palpebral reflex, orbital tightening, lateral recumbency, loss of righting reflex, supraglottic airway device placement, toe pinch, and general appearance. The scale showed construct validity, good to very good interrater reliability for individual items (6 raters; intraclass correlation coefficient, 0.671 to 0.940), very good intrarater reliability (5 raters; intraclass correlation coefficient, 0.951 to 0.987), and excellent internal consistency (Cronbach α, 0.947). The sedation scale performed well under the conditions tested, suggesting that it can be applied in a wider range of settings (different populations, raters, sedation protocols).

OBJECTIVE To evaluate the effects of providing 100% O 2 , compared with provision of room air, in sedated spontaneously breathing inland bearded dragons (Pogona vitticeps). ANIMALS 8 adult bearded dragons. PROCEDURES Animals were sedated with alfaxalone (20 mg/kg, SC) and received 21% O 2 (equivalent to room air) or 100% O 2 via face mask (flow rate, 1 L/min) in a randomized, blinded, complete crossover study (2-week interval between treatments). Sedation variables, cardiopulmonary variables, venous blood gas values, and postsedation food intake were evaluated. RESULTS Respiratory rate, heart rate, oxygen saturation, and sedation quality were comparable between treatments. Venous blood gas analysis revealed a higher total Pco 2 and HCO 3 - concentration for the 21% O 2 treatment. Postsedation food intake was not affected by the inspired oxygen fraction provided during sedation. CONCLUSIONS AND CLINICAL RELEVANCE The fraction of inspired oxygen did not appear to have clinically relevant effects on physiologic variables of bearded dragons during and after sedation. Therefore, provision of 100% O 2 can be considered for use in sedated bearded dragons without the risk of inducing hypoventilation. Similarly, failure to provide 100% O 2 would be unlikely to result in clinically relevant consequences in healthy sedated bearded dragons.

Objective: To assess the feasibility, success rate, onset, duration and extent of motor/sensory block following intrathecal injection of lidocaine in bearded dragons (Pogona vitticeps)., Study Design: Prospective experimental study., Animals: A group of eight adult bearded dragons (0.333 ± 0.048 kg)., Methods: The animals were sedated with alfaxalone (15 mg kg -1 ) subcutaneously. Neuraxial injections were performed with 1% lidocaine (2 mg kg -1 ) or 0.9% sodium chloride (0.2 mL kg -1 ) in all animals with a 7 day interval. If the initial injection did not result in motor block of the pelvic limbs within 10 minutes, a second injection was performed at the same dose. Measurements consisted of bilateral mechanical stimulation of limbs; 25%, 50%, and 75% of the trunk's length; and cloacal tone. Animals were monitored for any untoward side effects by monitoring heart rate (HR), respiratory rate, righting reflex and head position., Results: Success rate following the first injection of lidocaine was 50% (four out of eight animals) and increased to 75% (six out of eight animals) following a second injection. Onset of motor/sensory block occurred within 5 minutes in all successful injections. Duration and extent were variable, with most bearded dragons presenting motor/sensory block of cloaca and pelvic limbs (six out of six) and 25% of the trunk (five out of six) with mean ± standard deviation (range) duration of 49 ± 28 (25-100), 48 ± 25 (25-90) and 40 ± 14 (25-50) minutes, respectively. Confirmation of intrathecal injection by aspiration of cerebrospinal fluid was not possible. Neuraxial lidocaine significantly increased depth and duration of sedation, with a transient increase in HR, compared with saline., Conclusion and Clinical Relevance: Neuraxial lidocaine is a feasible technique with moderate success rate and low risk of complication in bearded dragons. This technique has potential for improving the management of anesthesia in this species., (Copyright © 2018 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

The objective of this study was to compare isoflurane with a combination of dexmedetomidine and ketamine, administered intramuscularly, for anesthesia in chinchillas (Chinchilla lanigera). In a prospective, complete crossover study, adult chinchillas (n = 8; age, 2 to 5 y) were anesthetized with a combination of dexmedetomidine (0.015 mg/kg IM) and ketamine (4 mg/kg IM). Atipamezole (0.15 mg/kg) was injected subcutaneously 45 min after dexmedetomidine-ketamine administration. For comparison, anesthesia also was induced and maintained with isoflurane in 100% oxygen, delivered by facemask. Anesthetic and physiologic parameters were recorded during each anesthesia, including various reflexes, heart rate, respiratory rate, body temperature, and SpO2. Food intake, fecal output, and body weight were recorded daily for 6 d after each anesthetic trial. Induction time, heart rate, respiratory rate, and body temperature did not differ significantly between the 2 anesthetic protocols. Recovery times were shorter and SpO2 was higher in animals that received isoflurane delivered in 100% oxygen. Food intake and fecal output were reduced in the dexmedetomidine-ketamine group for as long as 3 d after anesthesia, whereas isoflurane had no signifcant effect on food intake or fecal output. Both anesthetic protocols provided effective anesthesia in chinchillas. However, when anesthetized with dexmedetomidine-ketamine, chinchillas received room air and became hypoxemic. Future studies are needed to evaluate the effect of oxygen supplementation on anesthetic recovery and on the recovery of food intake and fecal output in chinchillas.

Blue poison dart frogs (Dendrobates tinctorius azureus) are commonly found in zoological institutions and are becoming popular in the pet trade. Sedation or light anesthesia is required for safe and effective handling of this species. In this study, the effect of subcutaneous administration of alfaxalone at two different doses (20 and 30 mg/kg) was evaluated in juvenile blue poison dart frogs (N = 10) in a prospective, randomized, blinded, crossover study. Heart rate, pulmonic respiratory rate, various reflexes, and behavioral parameters were monitored after drug administration. Both protocols resulted in rapid induction of sedation (median [range]) with loss of righting reflex: 20 mg/kg, 10 (10–20 min) and 30 mg/ kg, 10 (10–10 min). The time (mean ± SD) to return to spontaneous movement (20 mg/kg, 39.6 ± 7.6 min and 30 mg/kg, 54.5 ± 9.9 min; P < 0.01) and full recovery (20 mg/kg, 42.6 ± 8 min and 30 mg/kg, 61.6 ± 9.1 min; P < 0.01) after alfaxalone administration were significantly longer in the 30-mg/kg group. The frogs in both groups continued to remain responsive to tactile stimulation and retained palpebral reflexes. Alfaxalone induced cardiopulmonary depression and periods of apnea at both doses. The subcutaneous administration of 20 and 30 mg/kg alfaxalone resulted in clinically effective sedation in blue poison dart frogs. Sedation levels achieved in this prospective study would be adequate for a variety of noninvasive clinical procedures. [ABSTRACT FROM AUTHOR]

Tricaine methanesulfonate (MS-222) is a bath anesthetic agent commonly used in amphibians, but few studies have demonstrated its efficacy in a wide variety of anuran species. In this study, White's tree frogs (Litoria caerulea; n = 9) were used in a blinded, randomized, complete cross-over study to assess the anesthetic effects of two MS-222 concentrations (0.5 g/L and 2 g/L). Frogs were placed in MS-222 to induce chemical restraint. Heart and gular rates and palpebral, corneal, withdrawal, and righting reflexes were measured every 5 min. Frogs were removed from the anesthetic solution when reflexes were lost or after 25 min. Only mild sedation was induced with 0.5 g/L MS-222 after 25 min in all frogs, and surgical anesthesia was induced in all frogs with 2 g/L MS-222 within 5–20 min. Time from rinsing with distilled water to regaining reflexes in the 2 g/L group ranged from 10 to 43 min. There was a time-dependent decrease in heart rate with no significant difference between treatments. There was a significant decrease in gular rate for the 2 g/L dose compared to the 0.5 g/L dose. These results suggest that 0.5 g/L MS-222 can be used for mild sedation to facilitate diagnostic techniques, and 2 g/L MS-222 can be used to induce surgical anesthesia in White's tree frogs. [ABSTRACT FROM AUTHOR]

Blue poison dart frogs (Dendrobates tinctorius azureus) are commonly maintained in zoological institutions and are becoming popular in the pet trade industry. Sedation or light anesthesia is required for safe and effective handling of this species. In this study, the sedative effects of subcutaneously administered alfaxalone–midazolam–dexmedetomidine (AMD) (20, 40, 5 mg/kg, respectively) and ketamine–midazolam–dexmedetomidine (KMD) (100, 40, 5 mg/kg, respectively) were compared in a prospective, randomized, blinded, crossover study in juvenile blue poison dart frogs (n = 10). Both protocols were partially reversed 45 min after administration of either protocol with subcutaneously administered flumazenil (0.05 mg/kg) and atipamezole (50 mg/kg). Heart rate, pulmonic respiratory rate, various reflexes, and behavioral parameters were monitored after drug administration. Both protocols resulted in rapid loss of righting reflex [median (range): AMD, 5 min (5–5 min); KMD, 5 min (5–10 min)]. Time to complete recovery was similar with both protocols (mean ± SD: AMD, 97.5 ± 11.4 min; KMD, 96.5 ± 25.4 min). The AMD protocol resulted in pulmonic respiratory depression, whereas no significant difference in heart rate was found between the two protocols. All frogs were observed eating within 24 hr of chemical restraint. Gastric prolapses occurred in four frogs (AMD 3, KMD 1) that were easily reduced with a cotton-tip application. No other adverse reactions were observed. The results of this study provide two different subcutaneous chemical restraint protocols in juvenile blue poison dart frogs. [ABSTRACT FROM AUTHOR]

A retrospective review of sedation of lizards using dexmedetomidine-midazolam (DM) with or without ketamine administered intramuscularly or subcutaneously was performed. Forty-four sedation events, involving 25 individuals and 16 different species of lizards, were reviewed. Sedation was performed for physical examinations, imaging, biopsy collection, and wound treatments. Dexmedetomidine (median: 0.08 mg/kg, 25-75%: 0.05-0.1 mg/kg, range: 0.03-0.3 mg/kg) combined with midazolam (median: 1 mg/kg, 25-75%: 0.85-1 mg/kg, range: 0.5-2 mg/kg) was used in 11/44 (25%) sedation events. In 33/44 (75%) sedation events, ketamine (median: 2.9 mg/kg, 25-75%: 2.43-3 mg/kg range: 0.9-5 mg/kg) was administered in addition to DM. Insufficient depth of sedation was reported for 2/44 (4.5%) events. Atipamezole (10 times the milligrams dose of dexmedetomidine) and flumazenil (median: 0.05 mg/kg, 25-75%: 0.05-0.05 mg/kg, range: 0.01-0.1 mg/kg) were administered for reversal of the sedative effects of DM in all sedation events. The most common complication noted was apnea, which occurred in 2/44 (4.5%) sedation events and resolved following administration of the reversal agents. [ABSTRACT FROM AUTHOR]

Alpha2-agonist anesthetic combinations are often used in rodent anesthesia but no information about their effects on cardiac function in chinchillas exists. The purpose of this study was to utilize echocardiography to evaluate the cardiovascular effects of dexmedetomidine–ketamine anesthesia in chinchillas. Echocardiographic examinations were performed in eight adult chinchillas under manual restraint and following dexmedetomidine (0.015 mg/kg) and ketamine (4 mg/kg) administration. Dexmedetomidine–ketamine anesthesia resulted in a significantly decreased heart rate, fractional shortening, cardiac output, and flow velocity across the aortic and pulmonic valves, and significantly increased left ventricular internal diameter in systole. The observed changes in echocardiographic parameters are similar to those previously reported in chinchillas anesthetized with isoflurane. [ABSTRACT FROM AUTHOR]

Abstract: Intrathecal (subdural) administration of anesthetic and analgesic drugs in turtles and tortoises is a novel technique for the induction of spinal anesthesia and analgesia. Possible indications for spinal anesthesia include surgical procedures of the tail, phallus, cloaca, and hind limbs. Intrathecal injections are performed at the level of the coccygeal vertebrae. In red-eared sliders the intrathecal administration of lidocaine (2% preservative free, 4mg/kg) and bupivacaine (0.5% preservative free, 1mg/kg) provides regional anesthesia of the tail, cloaca, and hind limbs for about 1 and 2 hours, respectively. The intrathecal administration of morphine provides regional analgesia for up to 48 hours. Strict aseptic techniques should be used to avoid iatrogenic complications, and only preservative-free drugs should be injected into the intrathecal space so that spinal toxicity and secondary neurologic complications are avoided. [Copyright &y& Elsevier]

Abstract: The clinical use of anesthetic agents in reptiles presents a number of unique challenges because of the diversity of the class Reptilia with respect to natural history, size, anatomy, and physiology. Reptiles are commonly maintained as companion animals, widely displayed in zoological institutions, and many species serve as subjects in laboratory facilities. Therefore, to become a skillful clinician, developing an understanding of anesthetic efficacy across reptile species is important. The objective of this review is to provide a current perspective on the practical application of anesthetic agents in commonly maintained pet reptile species. [Copyright &y& Elsevier]