Brian,
A bit of further information : don't trust your dogs protection from the Lyme vaccine as well(it is far from 100% effective). My lab was vaccinated as soon as was allowed, we used Frontline as soon as allowed, and she still caught Lyme's and all the requisite problems that go with it. You really have to keep after those little critters.
Rick

"Sometimes too much to drink is not enough" Mark Twain