Zolazepam

To evaluate the efficacy of tiletamine-zolazepam (TZ) for sedation of red-eared sliders and to assess the effect of injection site location on sedation parameters.

Over a 1-month trial period, healthy turtles obtained from a rescue were administered TZ (10 mg/kg, SC) in the forelimb (FL) or hind limb (HL) in a randomized, blinded crossover design in a laboratory setting. Heart rate; respiratory rate; neck, forelimb, and hind limb muscle tone; pelvic limb withdrawal reflex; jaw tone; cloacal tone; and feasibility of positioning for jugular venipuncture were evaluated. Flumazenil at 0.05 mg/kg was administered SC 45 minutes after TZ injection for recovery. Time to first effects, total sedation score, and time to recovery were recorded.

There was no significant difference in mean time to initial sedative effects between FL (11 ± 4 minutes) and HL (14 ± 6 minutes) treatments in the study population (n = 8 turtles). Six of 8 turtles (75%) and 5 of 8 turtles (63%) in the FL and HL treatments, respectively, developed decreased muscle tone. Simulated jugular venipuncture was successful in 7 of 8 turtles (88%) in both treatments, although additional restraint was required in 3 of 8 turtles (43%) in the HL group. There was no significant difference in total sedation score at any time point between treatments, and median heart rate across the sedative period was similar between treatment groups. Mean time to recovery was similar between treatments (FL, 135 ± 55 minutes; HL, 165 ± 45 minutes).

Tiletamine-zolazepam (10 mg/kg) produced moderate sedation of red-eared sliders. The location of SC TZ injection administration did not significantly affect sedation parameters in this species.

Subcutaneous TZ can be used for sedation of red-eared sliders in clinical practice to facilitate examination and blood collection in this species.

Capture and handling of wildlife is essential to answering pertinent questions about ecology and biology. It is important to refine methods to increase animal welfare and safety. Gray wolves (Canis lupus) have been captured annually in Idaho, USA, for management or research purposes since their reintroduction in 1995-96. Two wolves died of hyperthermia during aerial darting in 2015. A retrospective analysis of 490 captures between 1999 and 2018 was conducted to identify factors that might contribute to the likelihood of hyperthermia (body temperature ≥41 C) when using anesthetic drugs in wolves. Wolves were captured in summer (May-October, n=321) by using foothold traps and anesthetized with ketamine-xylazine (n=66), ketamine-medetomidine (n=51), or tiletamine-zolazepam (n=204). Wolves were captured in winter (November-April, n=169) by using aerial darting with ketamine-medetomidine (n=75) or tiletamine-zolazepam (n=94). Mean body temperatures of wolves captured in summer were 39.7 C for ketamine-xylazine, 39.9 C for ketamine-medetomidine, and 39.5 C for tiletamine-zolazepam; in winter, mean temperatures were 40.4 C for ketamine-medetomidine and 39.1 C for tiletamine-zolazepam. In summer captures, hyperthermia occurred in 6/66 (9.1%) of wolves by using ketamine-xylazine, 7/51 (13.7%) by using ketamine-medetomidine, and 19/204 (9.3%) by using tiletamine-zolazepam. For winter captures, hyperthermia occurred in 20/75 (26.7%) of wolves by using ketamine-medetomidine and 7/94 (7.5%) by using tiletamine-zolazepam. Mixed-effects linear regression analysis was used to investigate the role of drug administration on initial body temperature while controlling for demographic and environmental factors. The top models supported effects of drugs administered on initial body temperature for wolves captured in both summer and winter. Ketamine, especially when combined with medetomidine, was associated with greater increased body temperatures than tiletamine-zolazepam, irrespective of season or method of capture.