Evaluation of anaesthetic regimens in guineapigs.

To establish reliable methods of chemical restraint and anaesthesia for mildly painful procedures in guineapigs, we compared the effects of the following anaesthetics and combinations of anaesthetics: tiletamine-zolazepam (two dosages), pentobarbital, methoxyflurane, ketamine-xylazine (three dosages), and ketamine-xylazine with methoxyflurane. Tiletamine-zolazepam induced a short period of chemical restraint but lacked analgesic effects at the doses tested. Although pentobarbital induced prolonged chemical restraint, the loss of responsiveness to painful stimuli was brief. Methoxyflurane alone induced transient anaesthesia and analgesia. Ketamine-xylazine combinations induced analgesia and chemical restraint of comparable durations, and some dosages were suitable for mildly painful procedures. The addition of methoxyflurane significantly potentiated the anaesthetic and analgesic properties of the high dosage ketamine-xylazine combination.