Y-shaped or H-shaped harness: no single design is best for every dog. The few studies available show that both families of harness change the way a dog walks slightly, that the differences vary from one dog to another, and that the choice should therefore be made dog by dog, with careful fitting. Here is how to recognise each design, what the studies say and how to choose.
Y, H and T harnesses: what are we talking about?
The names are not standardised and vary between manufacturers. What matters most for the dog’s comfort is the path of the front strap, the one that runs across the chest.
- Y-shaped harness. A strap runs up along the breastbone, splits in two at the entrance to the chest, passes in front of the shoulders and meets again on the back. Seen from the front, the harness forms a Y.
- Horizontal-strap harness, often sold as a “T” or “Norwegian” harness. A strap crosses the chest horizontally, runs along the side of the shoulders and joins the belly strap. Seen from above, the back strap and belly strap form a T with it.
- H-shaped harness. Two loops, one around the base of the neck and one around the ribcage, joined by a strap along the back (and sometimes under the belly). Laid flat, it forms an H. Look at where the front loop sits once the harness is on: depending on the cut, it behaves more like a Y or like a horizontal strap.
In the scientific literature, the comparison is almost always between two categories: the Y-harness, called “non-restrictive”, and the horizontal chest-strap harness, called “restrictive” because it was assumed to hinder the shoulder more. The results are more nuanced. For the basics, see our article on what a dog harness is for.
What the studies say about Y and H harnesses
A treadmill study that challenges the received wisdom
Lafuente, Provis and Schmalz (2019, Veterinary Record) filmed nine dogs at walk and trot on a treadmill, without a harness, then with a Y-harness and a horizontal-strap harness, with and without a 2.5 kg weight simulating pulling. Both harnesses reduced shoulder extension. Contrary to expectations, the reduction was greater with the Y-harness: 2.6° less at walk and 4.4° less at trot than with the horizontal harness. The authors conclude that harnesses do limit shoulder extension, “but perhaps not in the way originally anticipated”. Limitations: only nine dogs, and a treadmill, which alters natural gait.
Guide dogs on the ground: little difference on a lead
Weissenbacher and colleagues (2022, Animals) measured the ground reaction forces and stride length of twelve guide dogs on a pressure plate. When walked on a lead, neither the horizontal harness nor the Y-harness changed the measured parameters compared with a collar. Effects appeared when the dogs worked with a rigid handle under light pull, as when guiding a blind person: stride length was then shortened with the Y-harness. Limitations: few dogs, and a Y-harness they were not used to.
Sixty-six dogs, and results that change with breed
The largest study, by Williams and colleagues (2023, Journal of Applied Animal Welfare Science), analysed 66 dogs walking on a loose lead over a gait analysis mat, wearing two Y-harnesses and one chest-strap harness. The harnesses changed stride length, weight distribution and some forelimb angles, but not in the same way across breeds. For example, Cocker Spaniels and mixed-breed dogs had a shorter stride in the horizontal chest-strap harness, whereas Labradors and Springer Spaniels were not affected by it but had a shorter stride in a Y-harness than in their collar. The authors consider the distance from elbow to ground a key factor, and recommend choosing and fitting a harness on an individual basis, rather than following blanket recommendations on harness types.
A pilot study pointing the same way
Pálya and colleagues (2022, PLoS One) tested Y-harnesses and horizontal-strap harnesses on four dogs of very different sizes. Their conclusion: there is no absolutely superior harness, but the best one can be found for a given dog. With four dogs, no general conclusion is possible, as the authors acknowledge.
None of these studies followed dogs over several years: we do not know whether these small differences of a few degrees affect long-term health.
Comparison table: Y-harness or horizontal-strap harness
| Criterion | Y-harness | Horizontal harness (“T”, Norwegian) |
|---|---|---|
| Path of the front strap | Runs up the breastbone and splits in front of the shoulders | Crosses the chest horizontally, in front of the shoulders |
| What the studies show | Also reduces shoulder extension, sometimes more (Lafuente 2019) | Reduces shoulder extension; shorter stride in some breeds (Williams 2023) |
| Ease of putting on | Often goes over the head | Often nothing goes over the head, depending on the model |
| Watch out for | Neck straps too high or too close to the shoulders | Strap sitting too low and pressing on the front of the shoulders |
How to choose between a Y and an H harness
As the studies name no winner, start from your dog.
- Body shape. Long or short legs, broad or narrow chest, thick neck: the researchers note that the position of the same strap relative to the shoulders differs from one breed to another.
- The way your dog walks. A dog that pulls puts more load on the harness. Williams and colleagues note that the effects seen on a loose lead could be greater when the dog pulls. If that is your case, training remains the key: see what you can expect from a no-pull harness.
- Attachment points. A back ring suits calm walking; a front clip helps manage a dog that pulls, as long as the harness does not twist to one side.
- Ease of fitting. If your dog dislikes having something passed over their head, choose a model that opens with buckles.
If you are still torn between a harness and a collar, our comparison harness or collar covers it.
Checking the fit, whatever the shape
In the Weissenbacher study, the Y-harness was fitted so that the neck straps did not sit above the shoulder joint, with at least two finger widths of space between the belly strap and the front leg. Here are the checks to make, with your dog standing:
- Two fingers should slide flat under each strap, no more, no less.
- The shoulders stay free: no strap should press on the point of the shoulder when the dog reaches forward.
- The belly strap stays well away from the armpits, otherwise it rubs with every step.
- The harness stays centred while walking and does not twist. If it does, see what to check when the harness slides to one side.
- Your dog walks normally: no shortened stride, no legs lifting oddly.
Size is chosen by chest girth, measured just behind the front legs; weight is only a guide. Our size guide gives the chest girths for each size. Recheck the fit after a change in weight or a moult.
Frequently asked questions
Is a Y-harness the best for the shoulders?
Not necessarily. It is often presented that way, but the Lafuente study (2019) measured a greater reduction in shoulder extension with the Y-harness than with the horizontal harness, and the Williams study (2023) shows effects that vary between breeds. The authors recommend choosing on an individual basis and fitting carefully.
Is a horizontal-strap harness bad for dogs?
No, there is nothing to support that. In twelve guide dogs walked on a lead, it did not change their gait compared with a collar (Weissenbacher, 2022).
How can I tell if the harness bothers my dog?
Watch your dog walk from the side: shortened stride, redness or worn fur under the legs, reluctance to move forward. If there is lameness or pain, see your vet.
Sources
- Lafuente M.P., Provis L., Schmalz E.A. (2019). Effects of restrictive and non-restrictive harnesses on shoulder extension in dogs at walk and trot. Veterinary Record, 184(2), 64.
- Weissenbacher A., Tichy A., Weissenbacher K., Bockstahler B. (2022). Influence of Two Types of Guide Harnesses on Ground Reaction Forces and Step Length of Guide Dogs for the Blind. Animals, 12(18), 2453.
- Williams E., Hunton V., Boyd J., Carter A. (2023). Effect of harness design on the biomechanics of domestic dogs (Canis lupus familiaris). Journal of Applied Animal Welfare Science, 28(2), 301–317.
- Pálya Z., Rácz K., Nagymáté G., Kiss R.M. (2022). Development of a detailed canine gait analysis method for evaluating harnesses: A pilot study. PLoS One, 17(3), e0264299.