A good harness feels like it's not even there. An ill-fitting harness rubs, restricts movement, and in the worst case, comes off in the middle of a walk. The difference between them is almost always proper measurement, not price.
Why a Harness and Not a Collar
A collar concentrates all the pulling force on one point on the neck. For a dog that pulls, tugs, or gets excited by everything that moves, this puts direct pressure on the trachea. A harness distributes the force over the chest and back, which are much more resilient. This is especially important for dogs with short snouts, such as bulldogs, pugs, and shih tzus.
A collar is still useful for hanging an ID tag. Just not as the leash attachment point.
Two Measurements, Not One
- Chest Girth. The decisive measurement. Use a measuring tape around the widest part of the chest, right behind the front legs.
- Neck Girth. At the base of the neck, where the collar naturally sits.
Measure the dog while standing, not lying down, and with the fur flattened. If the dog falls between two sizes, take the larger one and tighten it. A harness that's too small cannot be made larger.
The Two-Finger Test
After tightening, you should be able to slide two fingers between the strap and the body at every point of contact. One finger is too tight. Four fingers means the harness is loose enough for the dog to escape as soon as it gets spooked by something.
Signs of Incorrect Size
- Thinning hair or red skin in the armpit: The strap is sitting too high and cutting in.
- The harness rotates sideways while walking.
- The dog shortens its front stride or appears constrained in the shoulders.
- You can pull the harness over the head without opening a buckle.
Puppies Grow Fast
A six-month-old puppy can go up a size within weeks. It's worth re-measuring every month until it reaches its full size, and choosing a model with four adjustment points instead of two.
If the dog has sensitivity in its neck, back, or shoulders, or reacts painfully to putting on the harness, it is advisable to consult a veterinarian before proceeding.