The free online encyclopedia Wikipedia includes an article on the word 'mushing.' After a few introductory lines about alternative meanings of the term comes this explanation (the many links go to related entries):
Mushing is a general term for a sport or transport method powered by dogs, and includes carting, pulka, scootering, sled dog racing, skijoring, freighting, and weight pulling. More specifically, it implies the use of one or more dogs to pull a sled on snow. The term is thought to come from the French word marche, or go, run, the command to the team to commence pulling. "Mush!" is rarely used in modern parlance, however; "Hike!" is more common in English. Mushing can be utilitarian, recreational, or competitive.The article delves into explaining the equipment used in mushing, the different hitching systems, the types of dogs preferred, and the various positions within the team, such as leader, wheel, swing, etc. Also interesting:
Mushing as a sport is practiced worldwide, but primarily in North America and northern Europe. Racing associations such as the International Federation of Sleddog Sports (IFSS) and the International Sled Dog Racing Association (ISDRA) are working toward organizing the sport and in gaining Olympic recognition for mushing. It is the state sport of Alaska.There is a collection of related pages at the Wikipedia entry for dog sledding.