How to Properly Fit and Adjust a Dog Harness

You've purchased a new harness for your dog, but now comes the critical step that many owners overlook: proper fitting and adjustment. A harness that's too loose can allow your dog to escape, while one that's too tight causes discomfort and can restrict movement. This guide walks you through the complete process of fitting and adjusting a dog harness for optimal comfort and safety.

Before You Begin: Getting Your Dog Comfortable

Before attempting to fit a harness, take time to help your dog feel positive about the experience. If your dog is anxious or fidgety around equipment, the fitting process will be much harder and potentially stressful for both of you.

• Let your dog sniff and investigate the harness before putting it on
• Offer treats while handling the harness to create positive associations
• Practice touching your dog around their chest, under their legs, and behind their front legs
• Keep initial fitting sessions short and positive

Step-by-Step Fitting Instructions

Step 1: Identify the Harness Type

Different harness styles go on differently. The three main types are:

• Over-the-head harnesses: The main loop goes over the dog's head, then you clip or buckle the remaining straps around the body
• Step-in harnesses: Your dog steps into two leg holes, and the harness fastens at the back
• Side-buckle harnesses: These unbuckle completely and wrap around your dog, fastening on the side or back

Step 2: Loosen All Straps

Before putting the harness on your dog, loosen all adjustment points. This makes it easier to get the harness on and prevents accidentally putting it on too tight. You can then gradually tighten each strap to achieve the proper fit.

Step 3: Put the Harness On

Depending on your harness type:

For over-the-head styles: Slip the head loop over your dog's head, ensuring the lead attachment point is on top (for back-clip) or at the chest (for front-clip). Then guide your dog's front legs through the appropriate openings and fasten any clips.

For step-in styles: Lay the harness flat on the ground. Have your dog step one foot into each leg hole. Then bring the harness up and over their back, fastening the clip at the top.

For side-buckle styles: Open all buckles. Place the harness against your dog's side, bring the chest strap under their body, and fasten. Then bring the back strap over and fasten at the top.

Adjusting Each Section

The Chest Strap

The chest strap runs across the front of your dog's chest, below the neck. This strap should:

• Sit low on the chest, not up against the throat
• Be snug but allow two fingers underneath
• Not rub against the armpits when your dog walks

The Girth/Belly Strap

This strap goes around your dog's ribcage, behind the front legs. It's usually the main point of adjustment on a harness.

• Position it at the widest part of the chest, just behind the front legs
• Ensure it doesn't sit on or restrict the front legs
• Apply the two-finger rule for proper tightness

The Back Panel (If Present)

Some harnesses have an adjustable back section. This should:

• Lie flat against your dog's back without bunching
• Not extend too far back toward the hips
• Distribute pressure evenly when the lead is attached

Common Fitting Mistakes to Avoid

Mistake 1: Harness Too Loose

A common error, especially with first-time harness users, is fitting the harness too loosely. Signs of a too-loose harness include:

• The harness shifts or rotates during walks
• Your dog can back out of the harness
• Large gaps between straps and your dog's body
• The chest plate hangs down rather than sitting snug against the chest

Mistake 2: Harness Too Tight

An overly tight harness is equally problematic:

• Visible marks or fur indentations after removing the harness
• Your dog seems reluctant to walk or has a stilted gait
• Difficulty fitting even one finger under the straps
• Chafing or redness on the skin

Mistake 3: Wrong Strap Positioning

Even a correctly-sized harness can cause problems if positioned incorrectly:

• Chest straps sitting too high can press on the throat
• Girth straps positioned over the front legs restrict movement
• Back panels sitting too far back can rub on the hips during walks

Testing the Fit

Once you've adjusted all straps, perform these tests to ensure proper fit:

The Movement Test

Have your dog walk around the house or garden. Watch for:

• Natural, unrestricted leg movement
• The harness staying in place without shifting
• No visible discomfort or change in gait

The Sit and Down Test

Ask your dog to sit and lie down while wearing the harness. The harness should remain comfortable in all positions without bunching, twisting, or pressing into their body.

The Pull Test

Gently apply pressure to the lead attachment point as if your dog were pulling. Check that:

• The harness doesn't shift or rotate
• Pressure is distributed across the chest, not concentrated on one point
• Your dog doesn't show signs of discomfort

The Escape Test

Some dogs are escape artists. While holding the lead, gently encourage your dog to back up. A properly fitted harness should not allow them to back out of it, even if they try.

Maintaining Proper Fit Over Time

A harness fit isn't a one-time task. Several factors can change how a harness fits:

• Weight changes: Recheck fit after significant weight gain or loss
• Coat changes: Dogs with seasonal coats may need adjustments between summer and winter
• Wear and stretch: Harness materials can stretch over time, requiring tightening
• Growth: Puppies and adolescent dogs need frequent rechecking as they grow

When Adjustment Isn't Enough

Sometimes, no amount of adjustment will make a harness fit properly. Signs you need a different size or style include:

• Running out of adjustment range (straps at maximum or minimum)
• Persistent chafing despite adjustments
• Your dog consistently seems uncomfortable
• The harness design doesn't suit your dog's body type

Don't hesitate to try a different harness if your current one isn't working. The right harness should be comfortable for your dog and easy for you to use. Use our measuring guide to ensure you're getting the right size, and consider your dog's breed and body type when selecting a style.

Taking the time to properly fit and adjust your dog's harness pays dividends in comfort, safety, and enjoyment for both of you. A well-fitted harness becomes invisible to your dog, allowing them to focus on the joy of the walk rather than uncomfortable equipment.