Teratogenic activity of pyrimethamine in Göttingen minipig.

Pyrimethamine (PY) was mixed with mashed feed and given to the Göttingen miniature pig (G-mini) during gestional days 11-35. Major malformations such as cleft palate, club-foot and micrognathia were observed in 11 out of 16 newborns from 3 pregnant sows which received 3.6 mg/kg/day. Two sows of a high-dose group (7.2 mg/kg) showed severe anemia and low appetite during the experiment and did not give birth. No malformation was found in 22 newborns of low-dose groups (0.9 and 1.8 mg/kg). Among 130 offspring which died before weaning out of 505 from 47 farrows in a breeding farm, major teratoses such as cleft palate were found in 8 newborns.