If your dog tests positive for internal parasites, your vet may prescribe Safe-Guard (fenbendazole) Canine 4 gm to treat and control those parasites. This product is effective against the four major types of parasites in dogs, including roundworms, hookworms, whipworms and taenia tapeworms. It’s easy to feed—just mix the powder into your dog’s food and make sure that your pup eats the full dose. You’ll need to repeat the dose for three days in a row. This deworming medication is considered safe for use in all dogs ages six weeks and older, including pregnant dogs.