OK, just to be sure I'm reading the packages correctly - The Advantage for Dogs is exactly the same as the Advantage for Cats? Imidacloprid: I-[(c-Chlor3-Pyridinyl)methyl]-N-nitro-2-imidazolidinimine 9.1% Inert Ingredients 90.9% So, a drop (.2ml) between the shoulder blades should be fine for ferrets, regardless of whether I have the package marked for dogs or cats, right? And.......I picked up a little girl this weekend who I've picked about a dozen fleas off of. The rescue I picked her up from have her a pretty good wet down with Marshalls flea spray....(worked about as good as water in my opinion). Says you can reapply in 3 days - does this mean I should be safe to use Advantage on her in 3 days instead?? Thanks - And Welcome to little Sweet Pea, a five year old silver mitt who was believed to be a boy all her life and has been through 3 families before me. 420 miles is the longest I've ever driven for a ferret pick-up, but she's worth every mile of it and this is truely her forever family now. [Posted in FML issue 3578]