Ugh! I found a tick on Mickey last month too!
Totally grossed and freaked me out! I think I have a tick phobia! But I thought I would pass on that yes, your dog can still get a tick if they are on advantage or frontline etc. And they can also still get Lyme disease even if they have had the shot! I now belong to a tick borne disease group and someone on there recommends spraying the yard with Ivory dish soap. It's supposed to be pretty effective but I haven't tried it yet myself. Of course, that only helps in your own yard. I also read that there is a micro fiber towel that you can use and if you go over your dog with that right after your walk, it's supposed to trap the bugs in it. Some people are going to try just getting any micro fiber towel and they'll post if it work, I might try that too!