Flea treatment for Cairn Terrier after vet visit

Your vet spotting flea dirt at a checkup is actually a common find — it means there's an active infestation and you need something that kills both adult fleas and their eggs quickly. The right treatment depends on your dog's weight, whether you want a spot-on or oral option, and whether tick cover matters where you live. What does your Cairn Terrier weigh, are you in an area with ticks, and has your vet suggested a specific treatment type or left it open to you?

Good — 6kg and otherwise healthy means most standard treatments are fine for her. At 8 she's a senior but that's not a concern with the products we'd normally reach for. Given that you need to tackle an active infestation and you have tick risk in Surrey, I want to make sure whatever you use kills fleas at multiple life stages, not just adults. Do you have any strong preference between a spot-on applied to the skin or an oral tablet? Spot-ons also give tick protection, which matters for your area.

Frontline original has had resistance issues in some flea populations, but Frontline Plus is a different formulation — it contains fipronil plus S-methoprene, which breaks the flea life cycle by stopping eggs and larvae developing, not just killing adults. That's exactly what you need when there's already an active infestation. It also covers ticks, which makes it right for Surrey. For a 6kg dog you'd use the small dog pipettes (2–10kg). Apply one pipette now, treat your home with a household flea spray at the same time — the environment is where 95% of the infestation lives — and repeat the spot-on monthly. I'd recommend Frontline Plus for Small Dogs as your immediate treatment.

Yes, it's well tolerated in older dogs and there are no age-related restrictions for an 8-year-old in normal health. Frontline Plus starts killing fleas within 24 hours of application and reaches full effect within 48 hours. Ticks are killed within 48 hours too. One thing to be aware of: you may see more fleas in the first couple of days as they become more active before dying — that's normal and not a sign it isn't working. The S-methoprene component keeps working on eggs and larvae for the full month. Treat your soft furnishings and her bedding with a household spray like Indorex at the same time and you'll break the cycle much faster.

Good — move quickly on the household spray too, ideally the same day. Wash her bedding on a hot cycle, vacuum thoroughly including skirting boards and sofa cushions, then apply the household spray to all soft surfaces. That combination alongside the Frontline Plus should clear the infestation within a few weeks. Keep her on monthly applications after that, especially through spring and summer when tick activity in Surrey is highest.