Tackling fleas, how soon to apply another topical medication?


TCS Member
Thread starter
May 15, 2017
We gave our cat advantage but didn’t think it was working too great so we gave it to him again 2 weeks later. We also have frontline but I’m not sure if it’s ok to give it to him only 2 weeks after the 2nd advantage dose. I’m also doing the normal things to take care of the infestation in the house like vacuuming and spraying but I still find fleas and baby fleas meaning the lifecycle is continuing. Is it ok to give the frontline?


TCS Member
Top Cat
Jun 13, 2018
Central FL (Born in OH)
The primary ingredients are different, but that is no guarantee that there wouldn't be an issue with the overlap. Neither one is supposed to enter the bloodstream, so that is a bit of a plus in my mind. However, I would ask your vet to see what they say. It may be that Adv doesn't work as well in your area (as my vet told me about where I live). Are you flea combing at least weekly as well?

I do know that Advantage II can actually be given weekly for serious infestations. I did every two weeks with Feeby for a while, and still in the long run we did not eradicate the fleas entirely. I still give it to her, because at 17+yo I am afraid of what else to use on her, and we are at least keeping the fleas to a minimum. We do vacuuming three times a week, and spray as well, but I have been having trouble getting her to cooperate with routine flea combings - so maybe that is our issue??

I guess if it were me, I would err on the side of caution, especially if your vet is 'on the fence' about it.