Most dog clothes are cut like doll outfits, which is why they ride up at the shoulders and gape under the chest. This one is shaped for a dog that actually moves: longer along the back than across the body, cut away underneath so it stays clean, and roomy enough at the front legs that it does not rub in the armpit. The fabric is soft cotton rather than the stiff polyester that makes dogs freeze and refuse to walk. Measure along the spine from collar to tail base and around the widest part of the chest, then buy on those two numbers rather than on your dog’s weight.