You might find it more helpful to treat your house and yard (and car if he goes there too) for fleas since 80% of the fleas are in the environment and not on the animal when there is a flea problem. I would use a flea spray that contains an insect growth regulator and is made for the house and not the animal. For the animal I will use DEFENDEX shampoo to rid it of the fleas on it. However other fleas in the house may jump on again later which is why I like to treat the house. Bathing the pet to get the flea debris off the skin is helpful in reducing the itchiness. Sometimes I will use a small amount of Frontline spray a few days after the bath if I have found any more fleas. I try to avoid using too many chemicals on the animal too close together.