Comparison of sedative effects of medetomidine-midazolam, acepromazine-butorphanol and midazolam-butorphanol in dogs

Sedative effects of medetomidine at 20 mu g/kg and midazolam at 0.3 mg/kg (MM), acepromazine at 0.05 mg/kg and butorphanol at 0.2 mg/kg (AB), and midazolam at 0.1 mg/kg and butorphanol at 0.2 mg/kg (MB) were compared in dogs. All dogs given MM were laterally recumbent within 11 min of the administration of the drugs, and this combination also induced deep sedation accompanied by analgesia and muscle relaxation, and strongly depressed arousal reactions to external stimuli. However, undesirable effects such as brad)cardia and decreased respiration were also observed in dogs given MM. Six of seven dogs given AB were laterally recumbent within 16 min of the administration of the drugs, and this combination induced relatively deep sedation but only a mild depression of arousal reactions to external stimuli. MB induced mild or moderate sedation with relatively large differences in effects among individuals. The recovery from sedation in each group was smooth and total recovery times were not significantly different.