Evaluation of dimethoate (Cygon 4E) for teratogenic activity in the cat

A commercial formulation (Cygon 4E), containing 47.3 percent dimethoate and 52.7 percent of unknown ingredients, was administered orally in single daily doses of time-mated cats between the 14th and 22nd day of pregnancy. The cats were necropsied on the 43rd day of pregnancy. Fetal values for survival, body weight, and skeletal and visceral anomalies were obtained following conventional methods. The highest dose, 12 mg/kg, was associated with polydactyl in eight of the 39 fetuses, whereas the 6 and 3 mg/kg doses produced no evidence of teratogenicity or embryotoxicity.