Dog Harness Rubbing Under the Arms? Chafing, Bald Spots, and Matting.
Naja YehiaShare
Dog Harness Rubbing Under the Arms? 5 Fit Mistakes Causing Chafing, Bald Spots & Matting
You take your dog’s harness off after a walk and notice the skin under the front legs looks pink, the fur feels rough, or worse — there’s a thin patch starting to form.
That is not your dog “just being sensitive.” As a groomer, this is one of the most common walking-gear problems I see. Owners assume the harness is safer than a collar, so it must automatically be comfortable too. Not true. A badly fitted harness can rub under the arms, break coat, create hot spots, and turn a daily walk into a slow-motion irritation problem.
The good news is this is usually fixable. If your dog’s harness is rubbing under the arms, here are the 5 biggest mistakes causing it — and exactly what to do instead.
Why harness rubbing happens in the first place
Harness rubbing is usually a friction problem.
Every time your dog walks, turns, pulls, lunges, or trots, the harness moves with them. If the straps sit too close to the armpits, slide side to side, trap moisture, or use rough material, that repeated motion starts acting like sandpaper against the skin and coat.
For short-coated dogs, that often shows up as redness, irritation, or thinning fur. For fluffy, curly, or long-coated dogs, it often shows up as coat breakage, tangles, and matting in the exact places the harness moves most.
The chest strap is sitting too far back
This is the biggest mistake.
A lot of harnesses sit closer to the armpit crease than owners realise. When the chest strap rides too far back, every step your dog takes creates rubbing right in that high-motion fold behind the front legs.
That area is sensitive, warm, and constantly moving. It does not take much friction to cause a problem.
Signs this is happening
- Redness behind the front legs
- Thinning fur near the armpits
- Your dog licking the area after walks
- Knots or matting exactly where the harness line sits
What to do
The chest section should sit forward enough to avoid cutting into the armpit crease. If the harness looks like it’s tucked right into the leg fold, it’s too close.
A good harness should guide movement without living inside the dog’s armpits.
The harness is too loose, so it twists and saws
A loose harness does not equal comfort.
When a harness is too loose, it shifts every time your dog changes direction. That side-to-side movement creates repeated rubbing, especially on one side. This is why some dogs only get irritation or coat damage on one underarm instead of both.
Owners often leave the harness looser because they are scared of making it “too tight,” but too loose is its own problem.
Signs this is happening
- The harness slides left and right
- The back panel rotates during walks
- One side rubs worse than the other
- Your dog can almost back out of it
What to do
Use the two-finger rule. You should be able to slide two fingers under the straps comfortably, but the harness should not flap, rotate, or drift across the body.
Secure, not restrictive, is the goal.
The material is too rough for your dog’s coat
Not all harnesses feel the same once they are actually on a moving dog.
A coarse webbing harness might feel “strong” in your hand, but on a dog it can be harsh on the coat and skin, especially if your dog pulls. Rough nylon, stiff edging, bulky seams, and scratchy mesh can all create friction.
This is even worse for Oodles, Golden Retrievers, long-haired small breeds, double-coated dogs, and dogs with finer or silkier coats.
Signs this is happening
- The skin looks fine but the coat is fraying or matting
- The harness leaves a rough line in the fur
- The rubbing gets worse when the dog pulls harder
- The harness feels stiff or scratchy around edges
What to do
Look for padding that feels smooth, breathable, and rounded at the edges. You want the harness to glide over the coat, not grip and drag against it.
If the inside feels abrasive to your hand, it will be worse on a moving dog.
Your dog is wearing the harness for too long
Harnesses are for walks, outings, and supervised wear — not all-day lounging.
A lot of owners leave the harness on for hours at home, in the car, during daycare, and between walks. The longer it stays on, the more time there is for heat, moisture, and friction to build up.
Even a decent harness can start causing issues if it is worn wet, worn all day, or left on while the dog naps and shifts around.
Signs this is happening
- Irritation gets worse in summer
- The area feels damp after a walk
- Your dog wears the harness for hours, not minutes
- Rubbing keeps happening even after fit adjustments
What to do
Take the harness off when the walk is over. Let the skin and coat breathe.
Also wash the harness regularly. Dirt, salt, sand, and dried sweat all make friction worse.
The harness shape is wrong for your dog’s body
Sometimes the issue is not just sizing. It is the actual shape.
Different dogs move differently. A deep-chested dog, a broad Staffy-type build, a fluffy Groodle, and a tiny narrow-framed breed do not all suit the same harness cut.
Some step-in styles and bulky strap layouts simply sit badly on certain bodies. If the shape fights your dog’s natural movement, you will keep seeing rubbing no matter how many times you adjust it.
Signs this is happening
- You keep adjusting it but it never sits quite right
- It dips into the armpits when your dog walks
- It looks fine standing still but shifts badly in motion
- Your dog seems reluctant when you bring the harness out
What to do
Choose a harness with thoughtful strap placement, multiple adjustment points, and a padded chest area that supports movement instead of crowding it.
A good fit is about body shape, not just size label.
How to tell if the rubbing is mild or serious
Mild rubbing
- Slight pinkness
- Flattened fur
- Minor roughness in the coat
- No broken skin
In this case, stop using the harness for a day or two, let the area settle, clean the harness, and refit properly before the next walk.
More serious rubbing
- Bald patches
- Obvious irritation
- Hot spots
- Broken skin
- Your dog licking or scratching constantly
At that point, stop using that harness completely until the area heals. If the skin is raw, inflamed, or worsening, get veterinary advice.
The fastest way to fix harness chafing
- Refit it using the two-finger rule
- Check strap placement while your dog is actually walking
- Remove it after walks instead of leaving it on all day
- Wash and fully dry the harness
- Switch to a smoother, better-padded harness if the material is rough
- Do not ignore coat breakage just because the skin “looks okay”
For fluffy dogs especially, coat damage is often the early warning sign before skin irritation gets worse.
What to look for in a coat-safe, anti-chafe harness
If you are replacing a rubbing harness, look for:
- Smooth padded lining
- Rounded edges
- Adjustable fit at multiple points
- A chest design that stays clear of the armpit fold
- Breathable structure for Australian weather
- Secure hardware that does not let the harness twist mid-walk
A harness should improve comfort and control at the same time. If it gives you control but destroys the coat, it is not a good harness.
Final thoughts
A harness rubbing under the arms is not something to “wait and see.”
Small friction problems become bald spots. Bald spots become irritation. And for curly or long-coated dogs, rubbing quickly turns into matting that ends up on the grooming table.
The right harness should feel secure, sit cleanly, protect the coat, and stay out of the dog’s natural movement lines.
If yours is rubbing, trust what you are seeing and fix it early.
Need a smoother, better-fitted option for daily walks?
Browse our curated harness collection and choose a design built for comfort, control, and coat safety.
Check out our other articles
Coat specific Harnesses
FAQs
Why is my dog’s harness rubbing under the arms?
Can a dog harness cause bald spots?
Can a dog harness cause matting?
Should a harness sit close to the armpits?
How tight should a dog harness be?
Should dogs wear harnesses all day?