Short answer
Re-measure your dog's chest whenever its body or coat changes: while it's growing, after a big groom or clip, when it moults or grows a winter coat, and if its weight changes. Re-check the adjustment more often than that, ideally with a quick look each time the harness goes on, because straps can loosen with use.
Re-measure or just re-adjust?
This article answers one question from our complete guide to how a dog harness should fit.
Re-adjusting means tightening or loosening the straps on the harness you have. Re-measuring means taking a fresh tape-measure reading of your dog's chest to check it still falls in the harness's size range. You'll re-adjust often and re-measure now and then, usually when the adjusters run out of room.
Puppies and young dogs
Growing puppies are the main reason to re-measure. A harness that fits at 8 weeks won't fit for long. We suggest checking a growing puppy's fit every couple of weeks, re-measuring the chest at the same time, and moving up a size when the measurement reaches the top of the current size's range.
Some breeds grow for well over a year: Canine Culture says German Shepherds are fully grown at around 18–24 months1. So we suggest you keep checking until the chest measurement stops changing, however old your dog is. Our puppy harness guides walk through each stage from 8 weeks to 12 months:
- Labrador puppy
- Golden Retriever puppy
- German Shepherd puppy
- Cockapoo puppy
- French Bulldog puppy
- Cavapoo puppy
- Border Collie puppy
- Springer Spaniel puppy
Coat changes and the seasons
Coats change through the year. Bailey & Coco says a Husky's chest measurement can change by 2–5 cm between winter and summer as the undercoat comes and goes2.
We suggest re-adjusting when your dog starts a heavy moult and again when the winter coat comes in. If the change is big enough that the adjusters run out, re-measure. See the Siberian Husky harness guide for more on seasonal fit.
After grooming
A full clip can take several centimetres of fluff off a long or curly coat in an afternoon, leaving a harness that fitted yesterday loose today. We suggest re-checking the fit the first time you put the harness on after every groom, and re-measuring after a big change of clip. Breeds that are clipped regularly include Poodles and Poodle crosses: see the Standard Poodle and Cockapoo guides.
Weight changes
Bailey & Coco says regular checks and adjustments are needed, "especially as your dog grows or if their weight fluctuates"3. If your dog gains or loses weight, re-measure and re-adjust. If your dog's weight changes and you don't know why, talk to your vet.
A new harness settling in
Webbing and buckles can settle in the first few walks. We suggest re-checking the fit after the first week of use, even if it was right on day one.
Everyday checks
Straps can loosen with use, and a harness can be put back on differently by someone else in the family. We suggest a quick look each time the harness goes on: front on the breastbone, girth strap clear of the armpits, clip in the middle of the back, and no twisted straps.
After walks, look behind the front legs and under the chest for red marks or rubbed fur. If you find sore or broken skin, stop using the harness and see your vet.
How to re-measure quickly
- Stand your dog square on a level floor.
- Wrap a soft tape round "the widest part of your dog's chest just behind the front legs", as Ruffwear describes it4. Keep it flat and snug, pressing through the coat to the body.
- Read the number in centimetres. Measure twice and use the larger reading.
- Compare it with your harness's size chart, or use our size finder.
More detail
Our complete guide to measuring your dog covers tricky coats, wriggly dogs and every other measurement.
Quick checklist
- Every time it goes on: quick look at the front, sides and clip.
- After the first week with a new harness: full fit check.
- Growing puppy: check fit and re-measure every couple of weeks (our suggestion).
- After a groom or clip: re-check the fit; re-measure after a big change.
- Moult or new winter coat: re-adjust; re-measure if the adjusters run out.
- Weight change: re-measure and re-adjust, and see your vet if you don't know the cause.
- Any rubbing or marks: re-check the fit. Sore skin: stop using the harness and see your vet.
Breed harness guides
Every breed fits a harness a little differently. These guides cover the sizes in each brand, how to measure that breed, and the styles that suit it.
- Labrador Retriever harness sizeSizes by brand, measuring and fit
- Siberian Husky harness sizeSizes by brand, measuring and fit
- Standard Poodle harness sizeSizes by brand, measuring and fit
- Cockapoo harness sizeSizes by brand, measuring and fit
Find your dog's harness size All breeds
Questions
How often should I re-measure my dog for a harness?
Whenever its body or coat changes: during growth, after a big groom, at a moult or new winter coat, and after a weight change. For a growing puppy, we suggest every couple of weeks.
How often should I adjust my dog's harness?
Give it a quick check every time it goes on, and adjust whenever the fit has changed. We suggest a full fit check after the first week with a new harness.
Do I need a new harness when my dog's coat changes?
Usually not. A Husky's chest can change by 2–5 cm between seasons, according to Bailey & Coco2, which adjusters can often absorb. If they run out of room, re-measure and check the size.
When is my puppy's harness too small?
When the straps are on their loosest setting and the fit is still snug, or the chest measurement is at the top of the size's range. Then it's time for the next size.
Why does the harness fit differently after grooming?
Because the harness sits on the coat, and a clip removes bulk. Re-check the fit after every groom.