Size: Medium.

Our New Christmas Dog Pajama.......will make your little angel a perfect 10 on the cuteness scale. It is made with soft Thermal Knit Cotton and features "Santa's Lil' Helper" Embroidered on the bottom. Very Adorable!!

Important Sizing Note: The following measurements are the dimensions of the actual product  not of the pet they fit. After measuring your pet  make sure all measurements fit within the following dimensions (with a little room to spare in the chest and neck). X-Small Chest: 10"-13" (Most Important) Neck: 7"-10" Pets Weighing: 3lbs.-5lbs. Small Chest: 13"-16" (Most Important) Neck: 10"-13" Pets Weighing: 6lbs.-10lbs. Medium Chest: 16"-19" (Most Important) Neck: 13"-16" Pets Weighing: 11lbs.-15lbs. Large Chest: 19"-21" (Most Important) Neck: 16"-19" Pets Weighing: 16lbs.-32lbs.