This study was designed to examine effects of $alpha$$_2$-Adrenergic Antagonists on blood chemical values in xylazine-sedated dogs. Twenty-four crossbred dogs of both sexes were intramusculary injected with a standard dosage of xylazine(2.2mg/kg of body weight). Righting reflex was uniformly lost and considered to be the point of maximum sedation. When the dogs were maximally sedated, tested groups were in-travenously injected with yohimbine 0.125mg/kg, 4-aminopyridine(4-AP) 0.3mg/kg, and a combination of yohimbine with 4-AP. Control group was intravenously 1 $mell$ of physiological saline solution. Total protein(T.P), albumin, glucose, aspartate aminotransferase(AST), alanine aminotrnasferase(ALT), blood urea nitrogen(BUN) were analyzed in the conditions of 0-, 30-, 60- and 120-minute after the administration of drugs. The results obtained in the study were as follows. 1. Changes of T.P, albumin, AST, ALT and BUN values in the control group were not significant during or after xylazine administration for at least 120minutes. 2. No changes of T.P, albumin, AST, ALT and BUN values in the tested groups were observed during or after $alpha$$_2$-Adrenergic Antagonists treatment. 3. Serum glucose values of control group were getting remarkably increased after xylazine injection. 4. The xylasine-induced hyperglycemia was reversed in the dogs administrated with $alpha$$_2$-Adrenergic Antagonists. Therefore, the results of the study show that the combined treatment with antagonists may be useful for accidental overdoses of xylazine and rapid reversal of animals sedated with xylazine.