Flea treatment for a 5-month Ragdoll kitten

Before anything else, there's a critical safety point with cat flea treatment that doesn't apply to dogs: permethrin and several other insecticides found in dog flea products are toxic to cats — and using the wrong product can be fatal. Always check a product is specifically labelled for cats. Now, to help you properly — how old and how heavy is your cat, is this an active infestation or are you looking to prevent one, and have you treated your home yet?

Good that you weighed her — that's exactly what matters here, not just the age. At 1.8kg she's above the threshold for most kitten-labelled products, but I want to check one thing: do you know if she's been treated for fleas before, or is this her first time?

That's a really common point of confusion. Those 'over 4kg' products are the adult-cat strength — they're not what you need here. At 1.8kg, your kitten fits perfectly into the small cat and kitten range, and there's a straightforward option: Advantage 40 for Small Cats and Kittens. It's a spot-on treatment, applied to the back of the neck, and the '40' refers to 40mg of imidacloprid — the dose calibrated for cats under 4kg, including kittens from 8 weeks and over 1kg. Your kitten clears both of those thresholds comfortably. It starts killing fleas within an hour and keeps working for four weeks. No permethrin, so it's completely safe for cats. One pipette, once a month.

Yes — this is important. Fleas on your cat are only about 5% of the problem. The other 95% are eggs, larvae and pupae living in your carpets, sofas and bedding. If you don't treat the home, the infestation will keep cycling back. Use an indoors flea spray that contains an insect growth regulator — something like Indorex Defence Household Flea Spray. It kills adult fleas and also stops eggs and larvae from developing. Vacuum thoroughly before you spray, then spray all soft furnishings and carpets, leave the rooms for 30 minutes, then ventilate well. One treatment usually covers the whole house. Do the home spray and the Advantage 40 on the same day if you can — that breaks the cycle from both ends.

Exactly right. Advantage 40 once a month, every month — consistency is what keeps fleas from coming back. As she grows, once she passes 4kg (Ragdolls can take a couple of years to fully fill out), you'd move up to Advantage 80, the adult cat version. But for now she's well within the small cat range. You've caught this early enough that one round of home treatment combined with monthly spot-on should clear things up without much fuss.