Don't forget this shirt before you take your pooch to the beach! Featuring a unique tropical island pattern, this snap button, soft thin cotton shirt is cool for the summer time. Leash hole. Measuring Guide: Back: Measure length of pet's back from the base of the neck to the base of the tail. Neck: Measure the circumference of the pet's neck for a snug, not tight fit. Chest Girth: Measure the broadest part of the chest. Note: If the dog has a stout build, select one size larger.