The nature of congenital limb defects induced in lambs by maternal ingestion of Veratrum californicum.

Groups of ewes were gavaged Veratrum californicum root-rhizome material over various 3 day periods during early gestation and their late-term fetuses examined. Resulting from gavage near day 29 were shortening of fetal metacarpal, metatarsal and tibial bones. Fibulae bowed severely when tibiae were shortened. Medial bowing of forelimbs at the fetlocks resulted from unequal shortening of fused metacarpi. Severe joint articular surface defects and arthrogryposis were present in some of the lambs from treatment ewes. There was bilateral and twinning symmetry in limb bone shortening. Severity of limb defects varied with gestational stage at time of gavage.