Sixteen adult beagles (10-12 kg) were used to evaluate combinations of 2,5-diaziridinyl-3,6-biscarboethoxyamino-1,4-benzoquinone (AZQ, aziridinylbenzoquinone), 1,3-bis-2-chloroethyl-1-nitrosourea (BCNU, carmustine), and cis-dichlorodiammineplatinum(II) (CDDP, cisplatin) administered by intravenous or intracarotid infusion. Moderate to severe systemic toxicities resulted from all drug infusions, but no histopathologic changes were found in the central nervous system (CNS) of any of the dogs. Results indicated that the toxicities were not dependent on the route of administration or the recipient's gender, and they were reversible in most cases with intravenous supportive therapy. Cisplatin seemed to have an additive effect when administered in combination with AZQ and/or BCNU.