In short: a harness connects your dog to the lead without pressing on their neck. It is useful for walks, especially if your dog pulls or is small, older or fragile, and there are specialised versions for sport, the car or support. It does not replace lead-walking training.
The harness has become the most common walking equipment after the collar. But what is it really for? Is it useful for every dog? And why are there so many shapes? Here are the essentials to understand before choosing.
The role of a harness
A harness is a set of straps that goes round your dog’s chest and shoulders. Its principle: spread the force of the lead across the body rather than the neck. When the lead tightens, the chest takes the strain, not the windpipe or the neck vertebrae.
Measurements on an artificial neck have shown that a collar pulled by the lead puts significant pressure on the neck, whatever the model (Carter et al., 2020). We go into these studies in Harness or collar: which should you choose?
When is a harness useful?
- Your dog pulls on the lead: the harness protects the neck while you work on lead walking. A front clip also helps guide them.
- Small dogs and dogs with a fragile neck: small breeds, short-nosed breeds, dogs who cough when the lead tightens.
- Dogs with certain eye conditions: pressure in the eye rises when a dog pulls on a collar, much less with a harness (Pauli et al., 2006). Your vet can advise you.
- Dogs who can slip their collar: a well-adjusted harness is harder to back out of.
- Older or recovering dogs: a handle on the back lets you help them up a step or back to their feet. There are also support harnesses designed for this.
- Visibility: reflective strips or stitching make your dog more visible in headlights at dusk.
When a harness is not essential
A dog who already walks on a loose lead, without jerking, can perfectly well go out on a flat collar. Nor is a harness a miracle cure: it does not teach your dog to stop pulling. With a back clip, some dogs even pull more, as a 2021 study of 52 dogs observed (Shih et al.).
The different types of harness
By shape
| Shape | Description | Points to watch |
|---|---|---|
| Y-front harness | The straps form a Y on the chest, between the front legs. | Often described as leaving the shoulders freer, which the only available study does not confirm (see below); check that the neck strap does not press on the throat. |
| Horizontal-strap harness (“Norwegian”) | A strap runs horizontally across the front of the chest. | Easy to put on; if the strap sits too low, it can hinder shoulder movement. |
| H harness | Two straps (neck and belly) joined on the back and under the chest. | Simple and light; needs careful adjustment so it does not slip. |
| Step-in harness | The dog steps into two loops, and you close it on the back. | Ideal for dogs who don’t like having something passed over their head. |
A small treadmill study (9 dogs) suggests that all the harnesses tested slightly reduced shoulder extension, and the so-called “non-restrictive” Y-front ones more than the horizontal-strap ones (Lafuente et al., 2019). This contradicts a widespread idea and still needs confirming on more dogs: the main takeaway is that fit matters as much as shape.
By use
- Walking harness: with a back ring, a front ring or both.
- Pulling harness (canicross, bikejoring, sledding): designed for the dog to pull, with an elastic line. It is not suitable for walking a dog who already pulls too much.
- Car safety harness: it connects to the seat belt or an anchor point. A walking harness is not designed to restrain a dog in a crash; choose a model made for this purpose.
- Support harness: to help an older, post-operative or disabled dog move around.
Back clip or front clip?
The back ring is comfortable for a dog who walks calmly. The front ring, on the chest, turns your dog towards you when they pull: this is the principle of so-called “no-pull” harnesses. In a 2024 study, dogs pulled less hard with a front-clip harness than with a collar (Johnson and Wynne). We take stock in Do no-pull harnesses really work?
Choosing and fitting it well
- Measure your dog, especially the chest girth, just behind the front legs. No tape measure? Follow our method without one.
- Compare with the manufacturer’s chart for the exact model: sizes differ from one brand to another.
- Adjust each strap and check that the harness does not twist or rub and leaves the shoulders free. The step-by-step guide is in How to put a harness on your dog.
Frequently asked questions
When should my dog wear the harness?
For outings on the lead. At home it is better to take it off, especially when your dog is left alone.
Can a harness hurt?
If badly fitted, yes: a strap that is too tight or sits in the armpit can irritate the skin or hinder walking. Check the fit regularly.
From what age can a dog wear a harness?
As soon as the puppy goes out on a lead, with gradual habituation. See our puppy guide.
If you are looking for a walking harness, you can compare our two models and their size guide.
Sources
- Carter A. J., McNally D., Roshier A. L. (2020). Canine collars: an investigation of collar type and the forces applied to a simulated neck model. Veterinary Record.
- Pauli A. M. et al. (2006). Effects of the application of neck pressure by a collar or harness on intraocular pressure in dogs. JAAHA.
- Shih H.-Y. et al. (2021). Dog pulling on the leash: effects of restraint by a neck collar vs. a chest harness. Frontiers in Veterinary Science.
- Lafuente M. P. et al. (2019). Effects of restrictive and non-restrictive harnesses on shoulder extension in dogs at walk and trot. Veterinary Record.
- Johnson A. C., Wynne C. D. L. (2024). Comparing efficacy in reducing pulling and welfare impacts of four types of leash walking equipment. PeerJ.