I had excellent results with Advantage (which kills the fleas when they bite the skin) on both the dogs and cats. Then we started having ticks, which Advantage doesn't help at all. So, now we use Frontline, and because of the mild winter we've had, I'm forced to use it year round on all 4 of them. We haven't seen a tick since I started using it and have had no problems with reactions to the topical medication.

Hope this helps.
Logan