Multicentre, randomised clinical trial evaluating the efficacy and safety of alfaxalone administered to bitches for induction of anaesthesia prior to caesarean section

Objective: To determine the clinical safety and efficacy of alfaxalone in bitches undergoing caesarean section (CS) and their puppies when it is administered for induction of anaesthesia followed by maintenance with isoflurane and oxygen and in conjunction with perioperative pharmaceuticals.

Design: A multicentre, randomised, positive-controlled clinical study.

Methods: A total of 74 bitches were enrolled in the study with 48/74 (65%) and 26/74 (35%) receiving alfaxalone and propofol, respectively, for induction of anaesthesia. Bitches were examined prior to induction and monitored during induction, surgery and recovery. Assessments were made for quality of induction, maintenance and recovery from anaesthesia. Assessments were made on pup viability for suction, dorsal flexion, withdrawal and anogenital reflexes.

Results: Of the 48 bitches receiving alfaxalone, 47 (98%) and 39 (81%) scored a top score of excellent for induction and anaesthesia effectiveness, respectively. For the same parameters with propofol in 26 bitches, 23 (88%) and 17 (65%) scored excellent. Average scores for recovery were not different between the two treatment groups with alfaxalone 46/48 (96%) and 25/26 (96%) of propofol induced bitches scoring a good or excellent rating. Bitches tolerated a number of concurrent medications throughout the peri-operative period. No bitch fatalities were observed in this study. There were no statistically significant differences between treatment groups for the puppy variables. Live puppies born by CS to bitches having been administered alfaxalone or propofol had similar survival rates 24 h after birth (i.e. 205/213 (96%) and 124/131 (95%), respectively).

Conclusion: This study confirms the safety and efficacy of alfaxalone for the purpose of anaesthetic induction for CS in the bitch. In addition, alfaxalone had a negligible effect on the neonate with >95% of puppies alive 24 h after the bitch had recovered from anaesthesia with alfaxalone induction.