Bugged

I used to think that if I could eliminate just one insect from the world that it would be the mosquito. Now, after a number of re-infestations I may change my mind and eliminate fleas.
We never, in the seven years of having our sheltie/shepherd mix, had a problem. One time before we used a flea product on her and when I took her to be groomed, was told that it wasn't fleas, but a skin problem which was easily solved with a moisturizer. Now, since have the little yorkie-poo, we have had nothing but fleas, fleas, fleas. Is it the dog, or our new location? I don't know, but I am REALLY sick of fleas!!