When buying a harness, start by measuring the base of your dog’s neck
and around their shoulder blades and chest bone with a tape measure. To ensure
the harness is the perfect fit you should be able to fit two fingers between
the harness and your dog, providing this doesn’t mean they can slip out of it.
Ensure you leave enough room to allow for your dog potentially holding their
breath when being measured. If you are buying for a puppy then always go a size
up so they can grow into it.