Safety of fenbendazole in swine

The safety of fenbendazole, an anthelmintic for use in swine, was tested by feeding 0, 25, 75, or 125 mg of fenbendazole/kg of body weight for 5 days. A dose-related transient leukopenia developed on day 7, but values returned to base line on day 15. In the groups fed 75 or 125 mg, sorbitol dehydrogenase activity increased on day 3 but returned to base line on day 10. Significant gross or histopathologic lesions were not found.