Use of guaiacol glycerine ether in clinical anaesthesia in the horse.

A total of 103 anaesthetic inductions were performed in horses for a variety of elective procedures. All cases were premedicated with acepromazine maleate (0.02 to 0.05 mg/kg body weight [bwt] intramuscularly [im]). In 50 cases (Group A) anaesthesia was induced by a single intravenous (iv) bolus of thiopentone sodium (11.1 mg/kg bwt or 1 g/90 kg bwt) followed immediately by a bolus of suxamethonium chloride (0.1 mg/kg bwt). In 53 cases (Group B) anaesthesia was induced using iv guaiacol glycerine ether (GGE) (approximately 50 mg/kg bwt) followed by a bolus of thiopentone at half the usual dose rate (5.6 mg/kg bwt or 1 g/180 kg bwt). Induction of anaesthesia was uneventful in both groups although in Group B it was particularly smooth. Following endotracheal intubation anaesthesia was maintained with halothane in oxygen administered via a circle system. The duration of anaesthesia was comparable between the two groups; however, the mean (+/- sd) time to standing in Group B, 35 +/- 22 mins, was significantly shorter than in Group A, 48 +/- 25 mins. The use of the GGE/thiopentone technique is discussed.