Pharmacodynamics of alfaxalone after single-dose intramuscular administration in red-eared sliders (Trachemys scripta elegans): a comparison of two different doses at two different ambient temperatures
Article first published online: 2 JUL 2013
© 2013 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia
Veterinary Anaesthesia and Analgesia
Volume 40, Issue 6, pages 590–598, November 2013
How to Cite
Shepard, M. K., Divers, S., Braun, C. and Hofmeister, E. H. (2013), Pharmacodynamics of alfaxalone after single-dose intramuscular administration in red-eared sliders (Trachemys scripta elegans): a comparison of two different doses at two different ambient temperatures. Veterinary Anaesthesia and Analgesia, 40: 590–598. doi: 10.1111/vaa.12061
- Issue published online: 17 OCT 2013
- Article first published online: 2 JUL 2013
- Manuscript Accepted: 23 APR 2013
- Manuscript Received: 25 SEP 2012
- Trachemys scripta elegans ;
This study compares the pharmacodynamics of two different doses of alfaxalone administered intramuscularly (IM) to red-eared sliders at two ambient temperatures.
Prospective blinded crossover experimental study.
Nine adult female sliders (Trachemys scripta elegans).
Following a 2-week acclimation at 22–25 °C, nine sliders were randomly assigned to receive alfaxalone, 10 mg kg−1 (W10), or 20 mg kg−1 (W20) IM. Each turtle received each dose, with a minimum 7-day washout period. A blinded observer evaluated heart rate (HR), palpebral and corneal reflexes, muscle relaxation, handling, and response to toe pinch at the following points: pre-injection, and 5, 12, 20, 30, 45, 60, and 120 minutes post-injection. Turtles then acclimated to 18–20 °C for 63 days, and the experiment was repeated in this lower-temperature environment, with treatment groups C10 (alfaxalone 10 mg kg−1) and C20 (alfaxalone 20 mg kg−1) subjected to the same crossover design.
C10 and C20 groups had significantly lower intraanesthetic HR than W10 or W20, respectively. C10 and W20 were significantly more relaxed and easier to handle than W10. No significant differences were observed in palpebral reflex, nor responsiveness to the toe pinch stimulus. None of the turtles lost corneal reflex. W20 and C20 had prolonged recoveries, compared to low-dose groups within the same temperature environment. Recovery was also longer at C20 and C10 compared to W10.
Turtles given 10 mg kg−1 were more relaxed and easier to handle in cold than warm conditions. Warm turtles were more relaxed and easier to handle when given 20 mg kg−1 than those given 10 mg kg−1. Cold conditions correlated with lower HR and longer recovery time for each dose category.
The turtles had dose-dependent and inconsistent responses to alfaxalone. Lower ambient temperature augmented the behavioral effects of this drug.