Comparative Anaesthetic Evaluation of Butorphanol, Dexmedetomidine or Acepromazine in Combination with Thiopentone Sodium for Inducing General Anaesthesia in Healthy Dogs

The present study was conducted to evaluate the anaesthetic efficacy of butorphanol, dexmedetomidine or acepromazine in combination with thiopentone sodium for inducing general anaesthesia in healthy dogs.

Eighteen adult dogs of either sex were randomly divided into three groups (ButTHIO, DexTHIO and AceTHIO) with six animals in each. Ten minutes prior to the anaesthetic administration, all the dogs were administered with glycopyrrolate @ 0.02 mg/kg I/M. The animals of group ButTHIO, DexTHIO and AceTHIO were premedicated intramuscularly with butorphanol @ 0.3 mg/kg b.wt., dexmedetomidine @ 10 μg/kg b.wt. and acepromazine @ 0.4 mg/kg b.wt. respectively. General anaesthesia was induced with thiopentone sodium @ 18 mg/kg b.wt. intravenously. Onset of sedation and anaesthesia, degree of analgesia, extent of muscle relaxation, duration of anaesthesia, complete recovery from anaesthesia and different reflexes were recorded for evaluation of anaesthetic efficacy.

The onset of sedation and induction of anaesthesia was quicker in group DexTHIO followed by AceTHIO and ButTHIO. Duration of anaesthesia and complete recovery were significantly (P<0.05) longer in group DexTHIO as compared to group ButTHIO and AceTHIO. Analgesia was excellent in all the groups but persisted for longer duration in animals of group DexTHIO. All the reflexes abolished completely with longer duration of muscle relaxation in group DexTHIO. It could be concluded that thiopentone sodium in combination with either dexmedetomidine or butorphanol or acepromazine can be used safely for inducing surgical anaesthesia in dogs. However, dexmedetomidine-thiopentone combination produced prolonged duration of anaesthesia with better quality for long surgical procedure in dogs.