Choosing the wrong dog harness wastes money and can actively harm your dog. A harness that restricts shoulder movement affects gait; one that sits on the throat defeats the purpose of using a harness over a collar; and one that’s too loose is an escape risk. This guide walks through every factor – clip type, fit, breed suitability and common mistakes – to help you buy the right harness first time.
Written by Hannah Reid, Certified Vet Nurse | Reviewed by a professional dog trainer
Step 1 – Understand Clip Types
BACK-CLIP: Lead attaches to the dog’s back. Natural position for walking. Best for: trained non-pullers, casual walkers, dogs with sensitive chests. Not suitable for: pullers (gives them full pulling leverage). FRONT-CLIP: Lead attaches to the chest. When dog pulls, momentum redirects them sideways. Best for: dogs in pulling correction training. Not suitable for: trained dogs on casual walks (front-clip creates lead tangling on legs). DUAL-CLIP: Both attachment points. Best versatile option – use front for training, back for normal walking.
Step 2 – Measure Your Dog
THREE KEY MEASUREMENTS: 1. GIRTH: Soft tape around the ribcage at the widest point just behind the front legs. This is the primary sizing measurement for most harnesses. 2. NECK: Circumference at the base of the neck where the collar sits. 3. CHEST WIDTH: Width across the chest between front legs (important for flat-faced breeds). Always use the brand’s specific size chart – ‘Medium’ means different dimensions across different brands.
Step 3 – The Two-Finger Rule
On a correctly fitted harness, you should be able to slide exactly two fingers under any strap – girth strap, neck strap, and chest strap. More than two fingers: too loose (escape risk, ineffective control). Less than two fingers: too tight (chafing, breathing restriction, gait limitation). Recheck fit after the first 3 uses – new webbing stretches slightly.
Step 4 – Breed-Specific Considerations
BRACHYCEPHALIC (Bulldogs, Pugs, Frenchies): Must use harnesses. Neck strap must sit at base of neck, not throat. Wide chest strap essential. GREYHOUNDS/WHIPPETS: Narrow heads can back out of over-the-head harnesses. Measure head AND neck circumference. TOY BREEDS: Choose lightweight hardware. Check escape-resistance carefully. LARGE POWERFUL BREEDS: Choose harnesses rated for their weight with reinforced attachment points. HUSKIES/ESCAPE ARTISTS: Double-lock clips and secondary security points are essential.
Step 5 – Check the Shoulder Movement Test
A common harness fitting mistake is straps that cross the shoulder joint, restricting natural forward stride. With the harness fitted, have the dog walk and watch their front leg motion. Each front leg should swing fully forward without any visible restriction. If the stride is shortened or choppy, the chest strap is too far forward – adjust or try a different harness style.
Common Mistakes to Avoid
1. Buying a harness that ‘fits now’ for a puppy – they grow out of it within weeks. 2. Choosing harness style before measuring the dog. 3. Using a walking harness as a car safety harness – they’re different products. 4. Leaving the harness on 24/7 – remove during unsupervised time. 5. Not checking for chafing under the armpits after the first 3 uses.
What to look for – expert buying advice
Common Questions
How tight should a dog harness be?
You should be able to slide exactly two fingers under any strap – not one finger (too tight), not three (too loose). This applies to the girth strap, neck strap and chest strap. A correctly fitted harness should not slip backward when you hold the back clip and gently pull – and should not allow the dog to back out when they reverse.
Should a dog harness be on all the time?
No – harnesses should be worn for walks and supervised outdoor activity only. Wearing a harness continuously causes fur matting under the straps, skin irritation from friction, and in rare cases the harness can catch on things and create a entrapment hazard during unsupervised time. Always remove the harness when your dog is home and unsupervised.
Can a harness hurt my dog?
A correctly fitted harness from a reputable brand should not hurt your dog. Harnesses that cause harm typically: (1) Are too tight, causing restricted blood flow or chafing, (2) Cross the shoulder joints and restrict gait, causing muscle strain over time, (3) Have narrow straps that concentrate pressure on sensitive areas. If your dog shows signs of discomfort – biting at the harness, reluctance to be fitted, limping after wearing – check the fit immediately.
Do vets recommend harnesses over collars?
Yes, for walking – the AVA (Australian Veterinary Association) recommends harnesses over collars for lead walking in most dogs, particularly brachycephalic breeds, dogs with neck or tracheal issues, and small breeds. Collars remain appropriate for ID tags and in-home use. The consensus position is: collar for ID, harness for walks.