Flea prevention for newly adopted cat

Congratulations on the new cat! Shelter cats often have patchy or unknown treatment histories, so starting fresh with a reliable prevention routine is exactly the right instinct. Before I get into options, there's one thing I always flag with cat flea products: permethrin and several other insecticides that are perfectly safe for dogs are genuinely toxic to cats — even some dog flea treatments left on skin or bedding can be fatal if a cat comes into contact with them. So it's really important to use a product made specifically for cats. Can you tell me roughly how much your cat weighs, whether you've noticed any signs of fleas already, and have you treated the home environment at all yet?

Good — 4kg puts her solidly in the standard adult cat weight range, so you've got the full range of options open to you. Since there's no active infestation and you just want clean, ongoing prevention, I'd point you towards Advantage (imidacloprid) spot-on for cats — specifically the Advantage 80 for cats over 4kg, which is the right strength for her. It's applied to the back of the neck once a month, kills fleas on contact so they don't even need to bite, and it's well-established as safe for cats. No permethrin, no organophosphates. Because she's just come from a shelter and you don't know her history, I'd also suggest doing one home treatment now — a household flea spray like Indorex — even without visible fleas, since flea eggs can be lurking in soft furnishings. But for her ongoing protection, Advantage 80 monthly is what I'd go with.

Yes, Advantage is available over the counter — no prescription needed. You can pick it up on Amazon UK or from most pet shops. That's part of why it's a practical first choice for a newly adopted cat: you can get it quickly without waiting for a vet slot. It's worth booking a general new-cat vet check soon anyway just to get her on record, but you don't need to do that before starting her on flea prevention.

Give it about 24 hours to fully dry and absorb before letting her onto soft furnishings or having lots of close contact. Once it's dry it's not going anywhere — it spreads through the natural oils in her coat. If you have children in the house, just keep them from handling her neck area on the day of application and you're fine after that.

Perfect. Set a monthly reminder so it doesn't slip — consistency is what makes spot-ons work well. And do consider the Indorex spray for the home at the same time; one can treats a whole house and lasts months. Enjoy settling in with her — sounds like she's landed in good hands.