Evaluation of Hypothermia for Anesthesia in Reptiles and Amphibians

Anesthesia and Euthanasia in Zebrafish

“…There is a plethora of data that demonstrate the decrease in nerve activity with decreasing temperature for mammals (Martin 1995), invertebrates (Westerfi eld 1978), and fi sh (Harper et al 1990;Prosser 1965). Prosser (1965) studied the peripheral nerves of catfi sh and showed that nerves from catfi sh (Ictalurus melas) that were acclimated at 24ºC were blocked at 3ºC, whereas nerves from those fi sh that were acclimated at 10ºC were blocked at 1ºC.…”

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

“…Despite the fact that hypothermia prolongs the anesthetic effects of alfaxalone in this species, the authors of this study recognize that intentional cooling is not an ethically appropriate method of intensifying anesthetic effect. Based on a wealth of physiological reptile studies, hypothermia is generally not regarded as an efficacious anesthetic strategy for this phylogenetic Class (Martin 1995). While both mammalian and reptilian peripheral nerve conduction velocities decrease with decreasing temperature (DeJong et al 1966;Rosenberg 1978), neuronal function has been demonstrated in tortoises at temperatures below which mammals are expected to develop conduction blockade (Rosenberg 1977).…”

AJVR Instructions for Authors

“…352,354,361 Hypothermia reduces amphibians' tolerance for noxious stimuli 376,377 and there is no evidence that it is clinically efficacious for euthanasia. 378 In addition, it is believed that freezing can result in the formation of ice crystals in tissues that may cause pain. 95,356 Consequently, because amphibians and reptiles lack behavioral or physiologic means of demonstrating pain or distress while hypothermic, generalized prohibitions on hypothermia for restraint or euthanasia are appropriate.…”