Determining the correct medication to use to deworm a dog of any age depends on what types of intestinal parasites the individual has. The best way to figure this out is with a fecal flotation. A veterinarian can perform this test on a sample of feces that you bring from home. Many puppies pick up roundworms and hookworms from their mothers, so oftentimes breeders and veterinarians will recommend deworming with a medication known to control these parasites even in the absence of the results of a fecal exam. Products with pyrantel pamoate as an active ingredient (e.g., Nemex, D-Worm, and Sentry HC WormX) are used for this purpose. Be sure to follow the label directions regarding dosing amounts and frequency and contact your veterinarian if a puppy develops gastrointestinal signs (vomiting, diarrhea, or loss of appetite) at any time. The following Dog Dewormers Buyer's Guide may help you compare some of the most common wormers available.