The Alaskan husky is a mix-breed of medium-sized working sled dog, developed specifically for its performance as such. Alaskan huskies are the most commonly used type of dog for competitive sled dog racing, both in short-distance sprint racing as well as long-distance expedition races such as the Iditarod Trail Sled Dog Race, the Yukon Quest, and the Finnmarkslopet. The Alaskan husky is not an officially recognized breed by any kennel club, nor does it have a formal breed standard.[citation needed] Unlike breeds developed for the show ring, the Alaskan husky is instead a product of careful selection for desirable sled dog traits from various other breeds, such as aptitude for pulling, endurance, speed, intelligence, appetite, and tolerance of extreme weather. (Source: Wikipedia.org, CC BY-SA)