When your dog can slip the harness
A harness they can't back out of
A dog who has slipped a harness once will try it again — and a harness that sits a hair loose is exactly how they get out into traffic.
Measure right around the widest part of the ribcage, just behind the front legs — snug, to the skin, not over the coat. That single number is what decides whether a harness holds.
Why we can put this in writing
Escape is a fit problem, not a product gimmick. Measure the chest and we return the harness size that actually closes on your dog — and we guarantee that fit or cover the swap. We don't promise a determined escaper can never get out; we promise the size is right.
“Escape-proof” is the maker's word — a snug, correctly-sized harness lowers escape risk but is not a containment guarantee. We guarantee the size, not that a determined escaper can't get out.
Want to compare the whole shelf instead? See all harnesses. Bringing home a new pet? Start with a starter kit.