How to Choose a Dog Harness: No-Pull, Sizing & Fit

A harness spreads the pull of the lead across your dog's chest and shoulders instead of their throat. For some dogs that's a comfort upgrade; for others — pullers, flat-faced breeds, small dogs with delicate windpipes, and any dog still learning lead manners — it's genuinely important for their health. This guide explains the types, how to measure and fit one properly, and how to pair it with a bit of training so walks actually improve.

Harness or collar — do I need both?

You need both, for different jobs. In the UK a dog must legally wear a collar with an ID tag in public, so keep a flat collar for the tag and identification. But walk on a harness, not the collar. A collar concentrates all the force of a pull on the neck; a dog that lunges or pulls on a collar can cough, gag, and over time risk damage to the throat and windpipe — a particular worry for small breeds and flat-faced dogs. A harness removes that risk and, with the right design, gives you more control with less force.

Front clip, back clip or both?

Where the lead attaches changes how the harness behaves:

• Back clip — the ring sits between the shoulder blades. Easy to put on, comfortable, and ideal for dogs who already walk nicely and for small dogs. The downside: it gives a committed puller something to lean into, sled-dog style.
• Front clip (no-pull) — the ring sits on the chest. When the dog surges forward, the attachment gently turns them back towards you instead of letting them power ahead. This is the design to choose if pulling is your problem; browse the no-pull range.
• Dual clip — rings front and back, the most flexible option. Use the front for training and busy pavements, the back for relaxed pottering. Our no-pull harness is a solid dual-purpose all-rounder.

A no-pull harness makes pulling far less rewarding and gives you control immediately — but it's a tool, not a magic off-switch. Pair it with the training below for lasting results.

How to measure your dog

You need two measurements, and a soft tape (or a piece of string you then measure against a ruler):

1. Chest girth — the widest part of the ribcage, just behind the front legs. This is the critical measurement. 2. Neck — the base of the neck, where a collar naturally sits.

Compare both against the size guide on the specific product — sizing varies between designs, so never assume your dog is "a medium". If your dog is between sizes, or has a deep chest (common in hounds and bull breeds), size up and adjust inward.

Getting the fit right

The test is simple: you should be able to slide two flat fingers under any strap. Any looser and a determined wriggler can reverse straight out of it — a real safety risk near roads. Any tighter and it rubs, especially in the sensitive armpit area, leaving bald patches or sores.

Check, too, that:

• Straps sit clear of the armpits — rubbing there is the most common fit complaint.
• The chest piece doesn't ride up into the throat.
• Your dog can walk, sit and lie down freely with a full range of leg movement.

Re-check the fit every few weeks for a growing puppy, and any time your dog gains or loses weight or coat.

Comfort features worth paying for

• Padding on the chest plate and wherever straps cross the body.
• Breathable mesh for warm days and longer walks.
• A grab handle on the back — brilliant for helping a dog into the car, steadying them in traffic, or a quick grab in an emergency.
• Reflective stitching for dark UK mornings and evenings.
• Quick-release buckles if your dog dislikes having things pulled over the head.

Actually stopping the pulling

The harness sets you up; a few minutes of consistent training does the rest:

• Be a tree. The instant the lead goes tight, stop dead. Only move again when there's slack. Pulling must never get them where they want to go.
• Reward the sweet spot. Treat and praise whenever your dog is walking near your side with a loose lead.
• Change direction. Turn and walk the other way when they forge ahead — it teaches them to pay attention to you.
• Use the front clip during training walks for extra steering while the habit forms.

Keep training sessions short and upbeat. Pair the harness with the right lead — a fixed 1.2–2m lead gives far more control for training than a retractable.

Puppies and growing dogs

A soft, fully-adjustable harness is gentle on a growing pup and starts good habits early. Just re-measure and re-adjust often — puppies change shape fast, and a harness that fit last month can quickly start to rub.

Frequently asked questions

Will a no-pull harness stop my dog pulling completely? It dramatically reduces it and gives you control straight away, but combine it with short, consistent loose-lead training for results that last.

Can my dog wear a harness all day? No — take it off at home and overnight so the skin can breathe and to avoid rubbing. Harnesses are for walks.

My dog escapes their harness — what do I do? Re-measure and tighten to the two-finger rule. For a committed escape artist, choose a design with an extra belly strap (a "three-point" or escape-proof harness).

Are harnesses bad for a dog's shoulders? A well-fitted harness that sits clear of the shoulder joint and armpit is fine for everyday walks. Avoid anything that cuts tightly across the front of the shoulders.

What size harness for a puppy? Measure now and buy adjustable; expect to size up at least once as they grow. Don't buy big "to grow into" — a loose harness is an escape risk.

A quick note: Everypaw is a pet-supplies shop, not a veterinary service. This is general advice on choosing and fitting everyday walking kit. If your dog is in pain, has a breathing problem, or you're unsure about fit for a specific condition, ask your vet. The PDSA and Blue Cross also publish free UK advice.

Browse dog harnesses, the no-pull range and matching leads.