For the last 6+ months I've de-flead the BorpCats with Frontline, which has worked fine. I heard about fleas becoming immune to Frontline, so this month I switched to Advantage. They were treated on 3rd July. Now, 9 days later, they are still scratching (not a lot, but a bit more than usual). I saw a live flea by BorpCat2's ear yesterday, and what I think is a few bits of flea dirt (not sure, it could just be general debris) on the sofa where he sits.
So, should I:
a) give them each another dose of Advantage now
b) order some Frontline and treat as soon as it arrives
c) order something else (what?) and treat with that
??
All advice gratefully received.