[Anesthesia by injection of xylazine, ketamine and the benzodiazepine derivative climazolam and the use of the benzodiazepine antagonist Ro 15-3505].

25 horses which entered the clinic for minor surgery, received ketamine (2.2 mg/kg i.v.) for induction of anesthesia after previous sedation with xylazine (1.1 mg/kg i.v.). As soon as the horses were in the lateral recumbency, the benzodiazepine derivate climazolam was administered at a dose of 0.1 mg/kg i.v. (10 horses) or 0.2 mg/kg i.v. (15 horses). The anesthesia was maintained with repeated injections of ketamine (1.1 mg/kg i.v. every 9-12 minutes). At the end of the surgery, 20 minutes after the last ketamine injection, Ro 15-3505, a benzodiazepine antagonist, was injected at a dose of 0.01 mg/kg i.v. or 0.02 mg/kg i.v. Climazolam successfully suppressed the adverse reactions of ketamine, such as poor muscle relaxation, hyperacusis and convulsions. The benzodiazepine antagonist Ro 15-3505 allowed good control of the duration of anesthesia and--in most cases--a smooth, predictable recovery period was the result.