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.

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.

Although our understanding of reptile analgesia continues to develop, μ-opioid receptor agonists are currently the most effective analgesics in a variety of reptile species. Fentanyl, a potent, short-acting, μ- and δ-opioid receptor agonist, is formulated for use as a transdermal therapeutic system (TTS) and was shown to be absorbed across the skin of prehensile-tailed skinks ( Corucia zebrata ). Snakes, which possess highly permeable skin, seem to be ideal candidates for effective transdermal analgesia. Fentanyl TTS (12 μg/h) was applied to the midbody, dorsal surface of two ball pythons ( Python regius ). Specimen mean body weight was 2.60 kg (2.20–2.99 kg). Cardiac blood samples were collected for 7 days, and plasma fentanyl concentrations were determined using high-performance liquid chromatography–mass spectroscopy. Therapeutic concentrations, as defined in mammals (1 ng/ml), were reached within 4 h of patch application, and they were sustained throughout the study. Plasma fentanyl steady-state (8.68–10.3 ng/ml) and maximum (11.7–17.6 ng/ml) concentrations were substantially higher than those demonstrated to attain analgesia in mammals, suggesting the potential to use smaller dosages. Patches remained well adhered throughout the study. Snakes exhibited no adverse side effects during the experiment. Data from this study suggest that the TTS delivers quantifiable fentanyl concentrations in ball python plasma and may serve as a route for prolonged analgesia administration to snakes. Additional research is needed to further determine treatment efficacy and safety and to optimize the dosing regimen.

Pain and analgesia are poorly understood in reptiles, which are commonly maintained in zoological institutions and as laboratory and companion animals. Thus, we developed a behavioral ethogram to evaluate pre-operative and post-operative responses to a thermal stimulus, feeding, movement, and breathing in red-eared slider turtles ( Trachemys scripta elegans ). We hypothesized that opioid drug administration would allow for a more rapid return to pre-operative behavior following a unilateral orchidectomy. The antinociceptive efficacy of morphine (2 mg/kg SC; mu-opioid receptor agonist) and butorphanol (20 mg/kg SC; mixed kappa-opioid receptor agonist and mu-opioid receptor antagonist) were evaluated because of their extensive use as analgesics in veterinary medicine. Compared to sham-saline turtles, surgery-saline turtles exhibited severely depressed feeding and increased movement at 2–8 h postoperation. Butorphanol did not alter feeding, movement, or breathing compared to saline in both sham- and surgery-treated turtles. Morphine depressed feeding and breathing for 1–2 days postoperation, but did not alter movement compared to saline except during the 2–8 h post-operation period. Our results show that pain in red-eared slider turtles is manifested as decreased feeding and increased spontaneous movement. Although turtles returned to normal behavior by 2 days following unilateral orchidectomy, a mu-opioid analgesic drug should be administered for at least 48 h following a surgical procedure.

ABSTRACT Nutritional myopathy was diagnosed in an adult male veiled chameleon, Chameleo calyptratus . The chameleon presented with a 1-yr history of progressive inability to use tongue, followed by profound weakness and circling. Histopathologic examination revealed generalized, subacute to chronic skeletal myopathy consistent with vitamin E and selenium deficiency seen in mammals.