To evaluate the cardiorespiratory effects of IV administration of propofol ( @ mg/kg ) , ketamine hydrochloride and propofol ( @ mg/kg each ; K-P ) , or ketamine hydrochloride ( @ mg/kg ) and diazepam ( @ mg/kg ; K-D ) before and after induction of anesthesia ( IoA ) in dogs sedated with acepromazine maleate and oxymorphone hydrochloride .