Janet
Joanne,
I stopped using all the Frontline crap years ago. I felt like I was just dumping toxics on my dog and slowing killing them. A friend of mine told me that coconut spray works well for keeping the fleas and tics off. I also use garlic in small amounts mixed with their homemade diet along with the coconut spray and haven't found a flea or tic yet.
Good Luck! I think if you go to www.greenpaws.org you will change your mind about using frontline.