Panacur is an FDA approved veterinary dewormer containing the active ingredient fenbendazole. It is most often used to remove hookworm, roundworm, tapeworm (Taenia) and whipworm. It is not effective against Dipylidium tapeworm infections.
It is able to kill parasites by damaging tubulin and intefering with the formation of microtubules. At higher doses it also disrupts metabolic enzymes and metabolic pathways. The medicine is sometimes used off-label to treat Giardia and lungworm infections.