Here is a article on all kinds of pests & preventatives
http://animalpetdoctor.homestead.com/Fleas.html
The American Dog tick is covered by revolution, not sure about the deer tick. Your vet wants you to buy a topical that will require you to buy a seperate heartworm med & return for more meds for earmites, another if your doggie gets a mange mite $cha ching$ I keep my dog protected from the discomfort of all that w/one med which is safer then being on several.