Panacur Dewormers help treat hookworms, roundworms, tapeworms, and whipworms in dogs or horses. Panacur Dewormers are also recommended to treat other gastrointestinal parasites as well. Panacur (aka Fenbendazole) is available in powder and paste form, which allow you to choose the best methods for your pet in order to stay away from any kind of worms.