Anaesthesia of hatchling green sea turtles (Chelonia mydas) with intramuscular ketamine-medetomidine-tramadol

Objective To characterise intramuscular ketamine-medetomidine-tramadol anaesthesia in hatchling green sea turtles (Chelonia mydas). Study design Prospective clinical trial. Animals Ten hatchling green sea turtles. Materials and methods Prior to anaesthesia, cardiopulmonary parameters, cloacal temperature, and venous blood gas and biochemistry were obtained from hatchling green sea turtles while they were being gently restrained. Animals were then anaesthetised with ketamine (5 mg kg(-1)), medetomidine (0.05 mg kg(-1)) and tramadol (5 mg kg(-1)) via intramuscular injection. Turtles were checked for the depth of anaesthesia at five-min intervals by recording reflexes (righting, palpebral, pinch, cloacal) and measuring heart rate, respiratory rate and cloacal temperature. After 20 min, a second venous blood sample was obtained for further blood gas and biochemical analysis and the medetomidine was antagonised using atipamezole (5:1 medetomidine, 0.25 mg kg(-1)). Results All turtles were successfully anaesthetised with a mean time to induction of 3.4 min (+/- 1). In all animals, a loss of reflexes (except for palpebral reflex) and voluntary movement was observed for the entire 20 min. Anaesthesia resulted in marked apnoea for the duration of the procedure. Venous blood gas and biochemistry analysis indicated that a 20 min period of apnoea had no measurable effects on venous blood gas results. All turtles recovered uneventfully after atipamazole antagonisation, with a mean time to first breath 4.5 min (+/- 3.7), and mean recovery time 15.5 min (+/- 15.4). Conclusions and clinical relevance Intramuscular ketamine-medetomidine-tramadol, antagonised with atipamazole appears to be an effective anaesthetic protocol in hatchling green sea turtles for short procedures with no deleterious effects on venous blood gases or biochemistry.