Turtles frequently require anaesthesia to enable veterinary examination and surgery although their unique anatomy and physiology means this can be difficult. A range of methods including injectable and inhalation anaesthetics are currently used but many of these have undesirable side-effects.
Alfaxalone is a steroid that is commonly used in small animal medicine and has also been used successfully in a range of reptiles but investigations into its use in turtles are rare and none exist for Australian species.
Although intravenous injection of anaesthetics provide a faster anaesthesia, it is not always possible to gain access to the veins in reptile patients and under these circumstances intramuscular administration of anaesthetic drugs may be advantageous.
If results are favourable then alfaxalone may become the anaesthetic agent of choice which will benefit animal welfare by increasing the safety of anaesthesia and reducing recovery periods.
To examine the effects of administration of intravenous and intramuscular alfaxalone as a sedative for veterinary procedures for turtles, using the Macquarie River Turtle (Emydura macquarii) as a case study.
Nineteen turtles were randomly assigned to one of two treatment groups. Alfaxalone was injected into either the right jugular vein (intra-venously) or left thigh muscle (intra-muscularly).
Turtles were monitored for heart rate, respiratory rate, cloacal temperature, time to regaining spontaneous movement and response to noxious stimuli.
Intravenous alfaxalone was an effective sedative in all turtles, although they maintained some reflexes during the experiment. This means it must be used in conjunction with pain-relief under circumstances where pain is expected to occur. However, intramuscular alfaxalone did not result in any sedative effects and is currently considered ineffective.
Primary researcher: Franciscus Sheelings (Veterinarian, Healesville Sanctuary)
Participating organisations: Zoos Victoria