Kills Fleas Fast- CapAction begins working within 30 minutes to kill fleas on your pet. In studies, CapAction achieved greater than 90% effectiveness against adult fleas on dogs within 4 hours and cats within 6 hours. Easy to Give -Remove the hassle of messy treatments with this easy to give flea control medication for both dogs and cats. CapAction is taken orally and provides protection that doesn' wash off of your pet.