The behavioral teratogenic potential of fenbendazole: a medication for pinworm infestation

Fenbendazole (FBZ) is a benzimidazole currently used for anthelmintic treat ment of pinworm populations in numerous animal species although it is not c urrently approved for laboratory rodents in the U.S. It has received consid erable interest for treating rodent populations due to its low toxicity, wi de safety margin and apparent absence of gross teratogenic effects. The pur pose of this study was to assess the behavioral teratogenic potential of FB Z. Pregnant rats were administered either FBZ-medicated feed at a therapeut ic level or normal rat chow throughout pregnancy and gestation. FBZ had no effect on pregnancy indicators such as maternal weight gain or water consum ption, number of pups born or pup birth weights. Offspring were examined in a variety of paradigms including righting reflex, negative geotaxis, runni ng wheel activity, Morris water maze (MWM) performance and digging maze per formance. FBZ offspring did show delayed righting reflex, some modest chang es in locomotor activity in a running wheel and minor alterations in perfor mance during the probe session of the MWM relative to controls. However, th e effects of FBZ on behavior were subtle and many of the behaviors examined were unaffected. These results suggest that FBZ may be an effective and re latively safe anthelmintic treatment for use in breeding colonies. (C) 2000 Elsevier Science Inc. All rights reserved.