Advantage 10 seems to be a popular one for fleas and ticks. Frontline Plus works for fleas, but not sure about ticks, however, some seem to have reactions to that so it depends on which you're most comfortable with using. For the years I've used Advantage, I don't think it prevented them from getting fleas so much as it helped to kill them off. It works to kill them when they bite your dog. It's been suggested that bathing your dog in regular Dawn Dish Detergent is the safest to rid your dog of fleas that are on it, but not so much to prevent them from hopping on for a ride. Hope this helps.
