Cumulative mortalities caused by clindamycin-induced CDAD in hamsters that were either untreated (⧫), treated q.d. with 0.2 (□), 1.0 (▵), or 5.0 (○) of oral vancomycin/kg, or treated with CDAD antitoxin at a 40-mg dose t.i.d. (×). Nineteen animals were used in the CDAD antitoxin treatment group, and six animals were used in each of the untreated and vancomycin-treated groups.