Measure you dog around the girth and this will give you the sizing required for the Lupine products;

When fitting the Step-In dog harness, once unbuckled, two openings are created for the paws. With one in each side, the adjustable sternum strap will fall between. Bring the ends up and around the dog's back and fasten the buckle between the shoulders. Adjust the front and back straps for a secure fit then adjust the sternum strap to a comfortably snug fit.
