I've been using them, and they only seem to be partially working (Frontline). When I put the drops on, I do part the fur, and manage to see some skin, but after they are on, he ends up with hair like it has gel in it on the back of his neck, like a kitty mohawk. (I call him the punk kitty when he has that.)
Do these always do this, or does this mean it's just going on the fur and not on the skin where it needs to be? If it isn't, how in the world do you really get it on their skin? I can only part enough to see a little skin at once...not enough for the vial. It ALWAYS gets on the fur after it's on for a minute or two.
Anyway, I think I'll switch to Advantage next time and hope it works better.