You might want to also consider using CapStar (
http://www.capstarpet.com/) - it's a pill that starts acting within 30 minutes of ingestion and will kill 99% of the fleas on your animal. However, it is only active in their system for 24 hours. And it's safe enough to give to dogs or cats - every day if need be. It's pretty amazing. A 6 pack runs around $40.
You might want to use this to kill the fleas already on your animal, then a topical such as frontline as a preventative.