This document discusses different types of working dogs and their roles. It focuses on military working dogs, including a 3-legged Belgian Malinois named Layka that was featured on the cover of National Geographic. Layka was wounded in Afghanistan but continued serving, and she recently skydived to test a new canine combat vest designed to improve performance and safety for military dogs. The document also briefly mentions sled dogs, therapy dogs including the first therapy dog Smoky in WWII, and the benefits of animal therapy.