Flea treatment still not working on my cat

It sounds like your Ragamuffin's flea treatment hasn't done the job — and two weeks in, still seeing live fleas is a real sign something's gone wrong with the approach rather than just the timing. Before I dig into what's likely happened and what to use instead, there's one critical safety point worth saying upfront: cat flea treatment has a serious constraint that dogs don't share — permethrin and several other insecticides that are perfectly safe for dogs are toxic to cats and can be fatal, so it's essential nothing crosses over. Can you tell me: how old and how heavy is your cat, which product did you use two weeks ago, and have you treated the home at all — carpets, soft furnishings, that kind of thing?

That explains a lot, honestly. Bob Martin spot-on drops are one of the most common reasons people come back saying treatment hasn't worked. They contain older active ingredients at concentrations that aren't reliably effective against modern flea populations — and at 5kg your Ragamuffin is a decent-sized cat, so underdosing is also a real possibility with those products. The other big piece is the home: up to 95% of a flea infestation lives off the animal — in carpets, bedding, and soft furnishings as eggs and larvae — so even a perfect on-cat treatment won't clear an infestation without addressing that reservoir. What I'd recommend switching to is Advantage 80 for cats. It's a vet-grade imidacloprid spot-on, kills adult fleas on contact within 24 hours, is specifically safe for cats, and your girl's weight puts her squarely in the right dosage band. Alongside that, you'll need to treat the home — Indorex Defence Household Flea Spray is the most effective option for that. Would it help to know exactly how to apply both, and when you should start seeing results?

Good question. You don't need to bathe her, but you should wait at least 48 hours after any bathing or shampooing before applying Advantage — and ideally the same gap since the last spot-on treatment, though two weeks is already well past that. Part her fur at the base of the skull so the liquid goes directly onto skin, and apply the whole pipette in one spot. Don't let her groom herself or be groomed by other pets for about an hour. For the home, vacuum thoroughly first — especially along skirting boards and under furniture — then apply Indorex to all carpeted areas and soft furnishings, leave the room for at least an hour, and ventilate well. One can covers up to 100 square metres. You should see a dramatic drop in live fleas on her within 24–48 hours of applying Advantage.

Not necessarily — and this trips a lot of people up. Advantage kills adult fleas on contact, but flea pupae in the environment can remain dormant for weeks and hatch gradually even after treatment. So you may well see the occasional flea jumping onto her for three to four weeks as that environmental reservoir clears. The key signs that Advantage is working are that you're not seeing fleas surviving or biting for long, and the numbers are clearly declining week on week. If you're still seeing large numbers of live, active fleas on her after five days, that's worth reassessing — but the far more likely scenario given you haven't treated the home yet is that you're dealing with ongoing reinfection from carpets and bedding. Get Indorex down as soon as possible — that's usually the turning point.

You're welcome — your Ragamuffin should be a lot more comfortable very soon. To recap: Advantage 80 applied directly to skin at the scruff, Indorex for the home after a thorough vacuum, and expect a few weeks for the full cycle to clear. If anything seems off or she has any unusual reaction after application, your vet is always the right call. Good luck.