Which harness is the right size?

First - measure your dog's girth. What's girth you ask? Measure around your dog's chest just behind your dog's front arm pits.

Girth 15"- 23" (13 - 58cm) - Small

Girth 23-29 inches (58 - 74cm) - Medium

Girth 29-37 inches (74 - 94cm) - Large

Adjusting your harness: The harness should be snug when your dog pulls, but loose and comfortable when your dog is not pulling.