Border Collie pulling on lead — best reward-based harness

A spray collar causing cowering is a real warning sign — that kind of stress response means the dog found it genuinely frightening, and it's right to move away from it. The most effective reward-compatible tools for pulling are no-pull harnesses and head collars, but which one fits depends on the dog's size, strength, and why they're pulling. For it to work well, fit is everything. Can you tell me what breed and size your dog is, how hard they pull, and whether you've tried any other equipment?

Good — stopping that quickly was the right call. A Collie going into anticipatory cowering after just a week tells you she made a strong negative association fast. That's actually typical of the breed; they're highly sensitive and very quick to make connections, which is exactly why reward-based training works so well on them. The lunging at specific triggers rather than constant pulling is also useful information — this is arousal-based pulling, not just general excitement, which means the tool needs to give you gentle physical control so you can interrupt and redirect before she locks on. For her, I'd go with the Perfect Fit harness in a T-bone front configuration. It has a front-ring attachment that turns her body when she pulls rather than punishing it, and it's made in modular sections so you can get the fit precise on a Collie's deep chest and narrow waist — generic harnesses often fit Collies badly and either slip or restrict movement. Pair the front ring with a double-ended lead clipped to the back ring too, and you have enough control to manage lunges while keeping the whole experience calm and positive for her.

No — a well-fitted harness has no aversive element at all, so there's nothing for her to fear. The only risk is rushing the introduction, which given what she's just been through you'll want to avoid. Spend two or three short sessions just letting her sniff it and putting treats on it before it goes anywhere near her body. Then practice doing it up and taking it off indoors with high-value treats the whole way through. Once she's relaxed with that, take her on a short lead walk somewhere low-distraction before you encounter the triggers she lunges at. The goal is that the harness predicts good things, not pressure. Given how quickly Collies form associations, a few positive repetitions and she'll be fine with it — probably faster than you'd expect.

The Perfect Fit website has the most detailed sizing guides and sells direct, but it's also available on Amazon UK if you want faster delivery. For sizing, measure the girth of her chest just behind her front legs, and the width of her chest between her front legs — Perfect Fit gives specific measurements for each module section on their site. At 18kg with a typical Collie shape you'll likely be in a medium body section with a narrower front, but measure rather than guessing. If you're at all unsure, their customer service is genuinely good and will walk you through it. Getting the fit right first time is worth the extra five minutes.

That's good to hear. The fact that she responded so clearly to the spray collar — as unpleasant as that was — actually tells you she's a sensitive, switched-on dog who'll respond just as quickly to getting things right. A properly fitted Perfect Fit harness with consistent reward-based work should make a real difference, especially once you start working on her trigger responses specifically. Good luck with her.