How do you get rid of fleas on a small dog completely?

I have two shih tzus, and we have tried EVERYTHING! Frontline doesn't work even. I am thinking they might be coming from the yard. Is there anything that can get rid of fleas completely? Also one of my shih tzus has some kind of 'allergy' to certain remedies. He acts neurotic when we put on any kind of flea powder or dip. He isn't like that with Frontline though.