Flea treatment Airedale Terrier spot-on failed

It sounds like the spot-on was applied incorrectly — which is more common than people realise with Airedales, because their thick, wiry double coat can easily block the product from reaching the skin. But before we fix the application issue, I want to flag something important: treating fleas effectively always means treating both the dog AND your home. Around 95% of fleas are actually living in your carpets, bedding and soft furnishings — not on your dog — so a spot-on alone will rarely eliminate an infestation even when used perfectly. To point you in the right direction: what size is your Airedale, roughly how bad would you say the infestation is right now, and have you treated the home at all yet?

Right, that's a clear picture — thank you. At 28kg he's firmly in the large-dog bracket, and daily live fleas plus sofa sightings tells me the home population is well established. The supermarket spray almost certainly won't have contained an IGR — an insect growth regulator — which is what actually breaks the flea life cycle by stopping eggs and larvae developing. Without that, you're only knocking back adults and the cycle restarts within days. Can I ask one more thing: where exactly were you applying the spot-on? With an Airedale's coat, the technique matters a lot.

Yes, that's almost certainly what happened. With a dense wire coat you really need to part the fur firmly all the way down to skin level — you should be able to see the skin before the pipette touches it — and it's worth applying in two or three spots along the back rather than just one, to help absorption. Now, for actually clearing this infestation, here's what I'd recommend. On the dog, switch to Frontline Plus for large dogs. It contains fipronil plus methoprene, which is an IGR, so it kills adults and also stops eggs hatching. It's well-established, widely trusted, and at 28kg he's well within the dosing range. For the home — and this is the critical part — use Indorex Defence Household Flea Spray. It's the gold standard for home treatment in the UK: it kills adult fleas on contact and the IGR keeps working for up to 12 months. Spray every room, under furniture, along skirting boards, and wash his bedding on a hot cycle first. Do the home treatment and the spot-on on the same day. You'll likely still see some fleas for a week or two as adults hatch out from existing pupae — nothing kills pupae directly — but they should stop appearing within 3–4 weeks.

There is some published evidence of reduced fipronil sensitivity in flea populations in parts of Europe, and it's a fair question. In the UK, resistance is not yet widespread enough to write it off — the majority of users with correct application and home treatment still get good results. The key word there is correct application, which is what was missing in your case. If you apply Frontline Plus properly and treat the home thoroughly with Indorex and you're still seeing live fleas on him after four weeks, that's when it would be worth asking your vet about prescription-only alternatives like Bravecto or NexGard — both of which use different active ingredients. But I'd give the correct protocol a proper run first before drawing that conclusion.

Good plan. Just to recap: Frontline Plus large dog, applied by parting the coat right down to skin in two or three spots along the back of the neck and between the shoulder blades. Indorex for every room, vacuuming first to wake up dormant pupae before you spray. Hot wash all his bedding the same day. Don't be alarmed if you see fleas for another couple of weeks — that's normal as the last pupae hatch and pick up the insecticide. Stick with the monthly Frontline after that and you should stay on top of it.