Flea treatment dosage for Scottish Straight cats

Before anything else, there's a critical safety point with cat flea treatment that doesn't apply to dogs: permethrin and certain other insecticides found in many dog products — and even some environmental sprays — are toxic to cats and can be fatal. Always check that whatever you use is explicitly labelled for cats. Now, to help you get the right dose for your Scottish Straight: how old and how heavy is your cat, is this an active infestation or are you looking at ongoing prevention, and have you treated your home yet?

Good that you're on it quickly. Scottish Straights tend to be solidly built cats and 5–6 kg is entirely plausible for a stocky female — so the weight ambiguity is worth resolving before you dose her. Most spot-on treatments split at 4 kg, with one pipette for cats up to 4 kg and a larger one for cats over 4 kg. If she's genuinely 5–6 kg, you'd want the larger pipette. Can you weigh her at home — even putting her in a box and stepping on the bathroom scales works — or ask your vet to confirm at your next visit?

Perfect, that makes it straightforward. I'd go with Frontline Plus for Cats — the pipettes for cats over 4 kg. It contains fipronil and S-methoprene, which kills adult fleas and also tackles flea eggs and larvae, which matters a lot when you have an active infestation. It's safe for cats, well-tolerated in adult cats of her age, and widely available. One pipette applied to the skin at the back of the neck, where she can't groom it off. You should see a clear reduction in adult fleas within 24–48 hours.

Absolutely treat the house — around 95% of a flea infestation lives in the environment, not on the cat. Use Indorex Defence Household Flea Spray or RIP Fleas Total Home Flea Spray, both of which contain permethrin and an insect growth regulator. One important note: remove your cat from any room you're spraying and keep her out until the spray has fully dried — permethrin in the air or on wet surfaces is dangerous to cats, even though it's safe once it's dried into fabric. Vacuum thoroughly before spraying, and wash her bedding on a hot cycle. Do the whole house in one session if you can.

Every four weeks for ongoing protection during flea season, or monthly year-round if she goes outdoors or you want continuous cover. During an active infestation, stick to the four-week schedule consistently for at least two to three months — flea pupae in your carpets can survive for weeks and hatch later, so you need the treatment active on her when they do. Once you're confident the environment is clear, you can reassess whether year-round or seasonal treatment suits your situation better.