We investigated the effects of yohimbine and atipamezole in dogs anesthetized with xylazine-ketamine combination on electroencephalography (EEG) . Experiment groups were divided into three according to antagonists . Saline (1 ml) was used as an antagonist in group C, yohimbine (0.1 mg/kg) in group Y and atipamezole (50 ug/kg) in group A. Each group consisted of 5 dogs. Glycopyrrolate was injected 15 minutes prior to xylazine injection. Xylazine (1.1 mg/kg, IM) and ketamime (10 mg/kg, IV) were injected with the interval of 10 minutes. After 15 minutes, antagonists were administered intravenously. For EEG measurements, a recording electrode was positioned at Cz, which was applied to International 10-20 system. Heart rates, body temperature, respiratory rates, arterial blood pressure, $PaO_2$