CapGuard is an oral tablet that kills adult fleas on dogs and puppies four weeks of age and older, and 25 lbs and over. CapGuard begins working within 30 minutes and achieved greater than 90% effectiveness against adult fleas on dogs within 4 hours and cats within 6 hours. A single dose of CapGuard tablets should kill the adult fleas on your pet. If your pet gets re-infested with fleas, you can safely give another dose as often as once per day. Each tablet contains 57 mg of Nitenpyram. Safe for use in pregnant or breeding dogs and cats.