Revolution flea treatment for dogs and cats is an all-in-one treatment that is easy to apply and offers coverage for fleas, heartworm, intestinal worms and other parasites. It is applied directly to the skin, and is both dry and waterproof after two hours. Used monthly, Revolution is absorbed into the bloodstream, skin and hair, killing any parasites on or in your cat or dog, as well as fleas within their environment. The product comes in a range of dosages and formulas appropriate for cats, dogs, kittens and puppies, and can also be used for rabbits. There are no agricultural insecticides in Revolution products. The active component in Revolution is called selamectin, which was designed specifically for cats and dogs.