I would hope most people are giving their dogs (and cats) monthly treatment for heartworm, and some of those have flea protection. We were doing Heartgard and Frontline, but Daisy started throwing up the Heartgard, and no way was I leaving an chance of her getting heartworms. We live in FLorida, and they frankly say an untreated dog is a dead dog.
We switched over to Revolution for all of them, and it does the same thing as both products together, and is cheaper for us. It works great for smaller dogs. For added protection you can buy Neem's Oil, which is non-toxic, and runs off fleas, ticks, chiggars, noseeums...and can be used in place of OFF, Repel, etc. An independent study showed it was more effective, not to mention SAFER, than deet.
My dh goes out in the swamp to photograph, and I made him stop using the commercial repellents because the dogs would lick him as soon as he walked in the door. The neem works in the swamp. I can sit outside at night and the mosquitos leave me alone.