I don't really waste my time on flea meds from pet stores. They never worked for me. Especially Hartz. The only place I know that sells single doses is the vet's office.

I have heard of a pill that can be ingested that works wonders... it's Capstar. A lot of people use it because they have problems with reactions to frontline because it's topical.

If you want to go the natural route, 1 tablespoon twice a day for a 50 lbs dog, of apple cider vinegar, is supposed to help regulate the digestive pH (something else it does), but it is also heard to repel fleas. Adjust according to your dogs weight.

And I would be careful with Advantage. It's not supposed to be used around cats, and I see you own one.