The drops like Frontline and Bayer Advantage work great (make sure you get them on the skin and not on the fur as best you can). They are expensive but worth every penny. We have a dog and three cats and live on a lake with lots of wildlife and these drops have saved our pets (from me killing them...). They take a few days to kick in but once they do you'll notice the fleas look drunk and are moving very slowly. You do still need to treat the yard, house, etc. but the drops will save your pet.