A two-year chronic toxicity and carcinogenicity study in the rat was conducted to determine potential adverse toxicological effects of CP 29242 (5ANTOGARD PVI) when added to the diet of rats at dietary levels (PPM) to provide daily intakes of 0, 50, 150, or 500 mg/kg bd.wt./day. Each experimental group consisted of 75 males and 75 females. Body weight was determined on each animal prior to initiation of the study at Day O, weekly during the first 14 weeks, bi-weekly from weeks 16 to 30, and every four weeks thereafter. Feed consumption was measured on 15 animals per sex per group prior to initiation of the study during weekly intervals when body weights were determined. Animals were observed daily for Clinical signs of toxicity and appearance of tumors. Blood biochemical and hematological parameters and urine urinalyses were conducted on animals sacrificed at 6, 12 and 18 months and at the termination of the study. All animals were necropsied and examined for gross pathological lesions; organs/tissues were preserved in 10% neutral buffered formalin for microscopic examination. Organs from animals at scheduled sacrifices were weighed after fixation for calculation of mean organ weight and organ-to-body weight ratios.