Dog harness (Y-Harness) - A little guide on measurement, biomechanics and build

[Tove09Tilda]

Hello everyone,

Some of you might already know that I am currently working on a Y-harness for my dog. During my research for this project, I noticed a recurring problem: many people try to build their own harnesses but miss several critical points. At the same time, there are surprisingly few good tutorials that explain not only how to build a harness, but also why certain design choices matter.

This guide is my attempt to change that. You are very welcome to contribute—whether by adding points I may have missed or by correcting information if something turns out to be inaccurate.

This guide is not intended for training purposes, provides no medical advice, and does not include product comparisons or commercial recommendations.

It is a design and fitting guide, grounded as much as possible in biomechanics. I am not a professional—just a science nerd who loves her dog and struggled to find properly fitting harnesses in stores. My goal is to share knowledge and reasoning, so you can make informed choices when designing or fitting a harness for your own dog.

In several parts, I will explain how to measure a dog for a harness and, more importantly, the reasoning behind those measurements and design decisions.

Before we dive into the topic : a few general words on harness building and materials. 

When building a harness, always ask about the intended use first, and only then look at the dog and honestly assess whether the harness type you have in mind is suitable. Some harness designs simply do not fit certain dogs—no matter how well they are made.

In my opinion, a harness must fit the dog first, and the purpose second.

When choosing fittings, always check:

• breaking strength

• maximum load

• overall size and weight

A practical rule I follow is:
maximum load = dog’s body weight × 4

Scale matters. A Dachshund needs very different (lighter) fittings than a Newfoundland. Oversized hardware adds unnecessary weight and can negatively affect balance and comfort.

Leather Choice (This Is Not Optional)

For leather harnesses, I recommend:

• 3–4 mm thickness

• normal to hard tempered leather (I personally prefer hard)

• leather from the butt or dorsal (spine) area

• preferably harness or bridle leather (For my own harness, I use Italian harness leather, double butt with a resin back. (Note: this particular leather is not suitable for equestrian saddlery work, but works well for dog harnesses.))

This type of leather stretches less over time and holds its shape better, which is essential if you want to use the harness for more than a few weeks.

Heavily oiled or fat leather is cheaper, yes—but it stretches significantly more and often has a very high breaking strength. In a worst-case scenario, we want the leather to fail before the metal fittings. If a dog gets caught and cannot slip out of the harness, it is safer for the leather to break than for rigid metal to hold indefinitely.

For animal welfare reasons: do not use heavily oiled or fat leather for harnesses.

Breed, Build, and Development

Breed and build must always be considered when fitting a harness.

For example:

• My current dog is long, mid-height, and slender

• My previous Springer Spaniel was long, sturdy, and rounder

• My mother’s dog is tall, long, slender, and overbuilt

Three dogs—three very different ideal harnesses.

Also consider how your dog may change with age. While growth and muscle development cannot be predicted perfectly, ignoring them entirely is a mistake. Some breeds are also more prone to injuries caused by ill-fitted harnesses, which makes proper fitting even more important. 

Part 1 – Biomechanics

As mentioned earlier: a harness has to fit the dog. The other way around is simply impossible.

The goal of a harness is to act as a leading device that interferes with the dog’s natural movement as little as possible. To achieve this, we must first understand canine biomechanics.

In this section, I reference several open-access scientific sources using APA 7 style, all linked at the end of this part. I will do the same in every following section whenever possible.

Harnesses and Their Effect on Movement

The way a harness distributes pressure across a dog’s body actively affects gait and overall movement.

Research on this topic is not entirely uniform:

• some studies show changes in spinal movement when a harness is used

• others show changes in stride length compared to walking on a collar

• some find little difference under certain conditions

What we can safely say is that harness design matters.

Many modern harnesses are marketed to restrict “undesirable” movement, such as pulling. This is not a long-term solution. If you are using a harness to prevent pulling, please work with a qualified trainer.

The main advantage of a harness is that it removes pressure from the neck and—ideally—distributes it more evenly across the body.

Stride Length, Shoulder Freedom, and Body Proportions

In a study by Williams et al. (2023), it was shown that the distance from a dog’s elbow to the ground is a key measurement when evaluating how restrictive a harness is on stride length.

This has practical consequences:

• Dogs with longer legs may benefit from a chest-strap harness rather than a Y-harness

• Smaller breeds often have relatively longer shoulders compared to forelimb length

• In these dogs, a chest strap may sit too high and actively restrict shoulder movement

The conclusion is simple but important:
no harness fits every dog.

Weight Distribution and the Kinetic Chain

A healthy dog carries up to 60% of its body weight on the forelimbs. The spine, shoulders, and limbs function as a single connected kinetic chain (Sürer et al., 2020). Even small changes in one area can alter overall movement patterns, affecting back motion and limb coordination.

Irregularities in movement are most easily detected at the trot.

An ill-fitted harness can, over time, lead to a shift of weight from the forelimbs to the hindquarters (Williams et al., 2023). One simple indicator for owners is to closely observe their dog’s movement on a collar versus in a harness.

Because dogs do not have a clavicle, the shoulder joint is a so-called “false joint,” stabilized primarily by muscle. Poor harness fit can affect both the scapula and the spinous processes of the spine.

Compensation and Injury Risk

Canine gait can be modeled in three dimensions and is normally symmetrical. This symmetry breaks down when the range of motion of any limb is restricted.

A study by Lin et al. (2020) demonstrates that dogs compensate rather than stop moving. Forward motion is maintained by redistributing forces—often until injury occurs.

Dogs are very good at hiding discomfort. This makes it our responsibility as owners and builders to ensure that equipment supports healthy movement instead of silently undermining it.

This concept is very similar to saddle fitting in horses.

A well-fitting saddle that allows the shoulder to glide freely results in smoother, more even movement. Girths and breastplates also offer useful parallels.

• The thoracic (belly) strap of a harness serves a similar function to a girth: keeping the equipment in place

• Like a girth, it must allow free elbow movement

• If it interferes with the elbow, stride length is restricted and weight shifts rearward

A breastplate in horses prevents forward saddle movement; in dog harnesses, the chest strap primarily distributes pressure and stabilizes the harness. Anything positioned in front of the shoulder has the potential to restrict stride extension and must therefore be fitted to the individual dog. This is a common shortcoming of chest-strap harnesses when strap width and placement are poorly chosen.

A Final Word on Restriction

For those who intentionally want to restrict their dog’s movement using a harness: be aware that restriction worsens under tension.

An open-access DAWGAIT dissertation shows that while a dog may appear to move normally at a walk, restrictions become evident at trot and gallop. What feels like “only a little restriction” can quickly turn into a real problem under load.

Personally, I use a harness to allow my dog to move freely in front of me. The leash is never tight—it is simply an extension of my arm, used for safety and communication. Our walks are calm, low-stress, and give my dog the freedom to explore while staying secure.

I also use harnesses as a secondary safety measure in new or potentially frightening situations, especially with young or insecure dogs.

Used thoughtfully and fitted correctly, a harness can be a valuable tool. Used carelessly, it can do long-term harm.

In the next part, I’ll show you exactly how I measured my dog for her new harness. I’m still waiting on some new tools, so updates might come a bit slower than I’d like—but I’ll share everything as soon as I can.

Sources: 

Lin, C.-C., Wu, C.-H., Chou, P.-Y., Chen, Y.-C., & Chen, C.-H. (2020). Evaluation of a multibody kinematics optimization method for three-dimensional canine pelvic limb gait analysis. BMC Veterinary Research, 16(1), Article 105.
https://doi.org/10.1186/s12917-020-02323-5

Sürer, E., Evangelisti, M. A., Paolini, G., Della Croce, U., & Manunta, M. L. (2020). A canine gait analysis protocol for back movement assessment in German Shepherd dogs. Veterinary Sciences, 7(4), Article 195.
https://doi.org/10.3390/vetsci7040195

Williams, E. R., Hunton, V. D., Boyd, J. A., & Carter, A. J. (2023). Effect of harness design on the biomechanics of domestic dogs (Canis lupus familiaris). PeerJ, 11, e14719.
https://doi.org/10.7717/peerj.14719

University of Georgia. (n.d.). DAWGAIT: Development and application of an open-source tool for canine gait analysis(Doctoral dissertation). UGA Open Scholar.
https://openscholar.uga.edu

 

[Mulesaw]

Very well written.

I think you might have made a small mistake in:

16 hours ago, Tove09Tilda said:

A breastplate in horses prevents forward saddle movement; in dog harnesses, the chest strap primarily distributes pressure and stabilizes the harness. Anything positioned in front of the shoulder has the potential to restrict stride extension and must therefore be fitted to the individual dog. This is a common shortcoming of chest-strap harnesses when strap width and placement are poorly chosen.

A breastplate on a horse prevents rearward movement. 

Looking forward to seeing how you are doing the actual measurement.

Good luck with the Internship in January

Brgds
Jonas 

[Tove09Tilda]

22 hours ago, Mulesaw said:

Very well written.

I think you might have made a small mistake in:

A breastplate on a horse prevents rearward movement. 

Looking forward to seeing how you are doing the actual measurement.

Good luck with the Internship in January

Brgds
Jonas 

Thank you! 
Ah! Yes, that was definetly a mistake due to sleepiness. My trainer would yell at me as we just had a discussion about martingals and when and when not to use them. 😆
The measurement part, is currently in wirting and I hope to have publish ready this evening. 
And again thank you! I hope to learn a lot and maybe even find a new calling. I'm literaly sick and tired of pro-bono work by now and constantly having to fix the issues non-certified consultants caused. They get paid a lot of money, I don't even see a cent while doing the work they promised to do but failed to deliver - I don't think I have to say more. 😅 

[Tove09Tilda]

Part 2 – Measuring Your Dog

This part is much more hands-on. You will see photos and graphics and get an explanation for every single measurement, so you can fully understand what you are measuring—and why it matters.

Before we start, I want to introduce the dog who will be the model for all graphics and pictures in this guide.

Meet Tova

This is Tova. She is almost three years old and an English Setter mix from Tuscany, Italy. I got her when she was imported to Germany at six months of age. Since then, we’ve been a team—chaotic, playful, and always on the lookout for an adventure.

When I got her, I already had years of experience with dogs and their equipment. Still, I quickly realised that I didn’t know everything.

It started with collars and ended with constantly ill-fitting harnesses. The harnesses she wore caused discomfort over time, especially for her long back—and that was on me. They were always some unfortunate mix of too large in one place and too small in another, and I didn’t spot the problem early enough.
She is the reason I want to do better.

So, how do we actually do better?
By measuring our dogs correctly.

 

General Measuring Rules

- Take each measurement three times

- Let your dog move a few steps between measuring rounds

- Later, before cutting leather, check each strap length three times

- Precision matters. Your dog will thank you.

 

What You’ll Need

• Chalk (as soft as possible) or any non-toxic, non-permanent marker that shows on fur
• A flexible tape measure
•  Something to write on
•  Something to write with

What We Are Going to Measure

• Neck circumference (in front of the sternum, below collar position)
• Elbow to floor
• Elbow to elbow
• Distance between the shoulder blades
• Torso circumference (widest part of the ribcage)
• Distance from chest to torso
• Distance from neck to widest part of the ribcage

 

Before Measuring: Position and Anatomy

Before taking any measurements, we need to understand the anatomy of the individual dog in front of us.
Your dog should stand directly in front of you. I was able to measure Tova on my own, but if your dog is more active, get someone to help hold them calmly.

Make sure:

• all four paws are on the ground
• the paws are as parallel as possible
• the dog stands “closed” (equestrians know exactly what I mean)
• Now grab your chalk—and a good amount of patience.

Marking Anatomical Landmarks (This Is the Key Step)

1. Shoulder Line

First, locate the shoulder and draw a line along it.

In my photos this may be hard to see because Tova has her winter coat and the chalk didn’t show as well as I hoped. If you’re unsure what to look for, Figure 1 will help.

Repeat this on both sides, then connect the lines across the neck and chest.

2. Shoulder Blade Positions (Static and Dynamic)

Next, locate the shoulder blades and mark each side with a dot or cross.

Now lift one front paw as high as your dog normally lifts it while walking. Feel for the shoulder blade again and mark its new position in the same way.

This shows you how much the shoulder blade actually moves.

3. Elbow Movement Zone

With the paw still lifted, locate the elbow and draw a vertical line marking its range.

Repeat this for both sides.

 

4. Widest Part of the Ribcage

Now locate the widest part of the ribcage.

Some companies recommend measuring “one hand behind the elbow.” From observing different conformations, I’ve found that this rule of thumb does not consistently hold true.

Instead, visually and manually identify the widest point and mark it with a vertical line on both sides.

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At this point, your dog will look like a child discovered abstract art.

Now is also a good moment to calmly reassure your partner or other dog owners or concerned bystanders, that yes—you are completely fine.

These chalk lines are our guides. They show us where movement happens and where straps must not interfere. Our motto here is very much work smarter, not harder—especially if your dog is not the calmest individual.

 

Taking the Actual Measurements

1. Neck Circumference

Using the shoulder line you drew earlier, measure above this line and around the neck, between the chalk line and the collar position.

The tape should sit flat

You should be able to slide at least one finger underneath

If this measurement does not fit over your dog’s collar, that is not a problem. This will make sense later when we translate measurements into design.

2. Torso Circumference (Widest Ribcage Point)

Use the vertical chalk lines marking the widest ribcage point as your guide.
Measure all the way around the torso. Keep the tape level and as vertical as possible

Now cross-check with the elbow movement lines:
there should be at least two finger widths between the torso strap position and the elbow movement zone
If not, move the measurement slightly backward. Elbow clearance is non-negotiable.

3. Distance Between the Shoulder Blades

Measure the distance between the dynamic shoulder blade markings (the lifted-paw positions).

This measurement tells you how wide the dorsal (back) strap is allowed to be.

In Tova’s case, I ended up with less than one inch of usable space during movement. This means:
the strap must be narrow, padding must be minimal and carefully planned

Ignoring this leads to direct scapular restriction.

4. Distance from Chest to Torso (Between the Front Legs)

Measure from the chest/sternum area back to the widest ribcage point between the front legs.

This measurement defines how long the chest strap is allowed to be without drifting into the elbow movement zone.

 

Measurements That Seem Odd—but Matter a Lot

5. Elbow to Floor

Measure from the lowest point of the elbow straight down to the floor.

This measurement tells us:

• how low a chest or Y-strap may sit
• where vertical restriction begins
• whether a harness design risks interfering with stride extension

This is especially important for chest strap and Y-harness designs as this measure give us an overview of the swing radius of the dog.

6. Elbow to Elbow

Measure horizontally from one elbow to the other.

This measurement defines:

• how wide a chest strap or Y-front can be
• how much lateral freedom the forelimbs need

Too narrow causes pressure and rubbing.
Too wide pushes straps into the shoulder joint.

Now take these measurements another two times until you have 3 measures for each measurement point. 

Caption: This is written in german and says Neck, Elbow, Torso, Chest, Elbow to Elbow, Back 

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Final Note for This Part

If a strap crosses a chalk movement zone, it will interfere with movement—no matter how well it “fits” on paper.

Measurements are not just numbers.
They are boundaries defined by anatomy and motion.

In the next part, we’ll use these exact measurements to:

• choose the appropriate harness type
• and translate them into a functional design

This is where everything starts to come together. 

 

Edited 5 hours ago by Tove09Tilda