Sled Dogs run because they love to run, they are born and raised to it. How they run is a product of how they are trained. If they are well trained they will run in perfect harmony. Several distinct dog breeds are in common use as sled dogs, although any medium-sized breed may be used to pull a sled. Purebred sled dog breeds range from the well-known Siberian Husky and Alaskan Malamute to several overlapping local populations of arctic and subarctic sleddogs
Sled dogs are expected to demonstrate endurance and speed. Endurance is needed to travel the distances demanded in dogsled travel, which may be anything from five to eighty miles (8 to 130 km) or more a day. Speed is needed to travel the distance in a reasonable length of time. Racing sled dogs will travel up to an average twenty miles per hour (32.2 km/h) over distances up to 25 miles (40 km). Sled dogs have been known to travel over 90 miles in a 24 hour period while pulling 85 pounds each. Sleddogs pull various sorts of sleds, from the small 25 pound (11 kg) sprint-racing sleds, through the larger plastic-bottomed distance racing toboggan sleds. A team of sled dogs may consist of anywhere from three to two dozen dogs. Racing sleddogs wear individual harnesses to which individual tuglines are snapped, pulling from a loop near the root of the tail. The dogs are hooked in pairs, their tuglines being attached in turn to a central gangline. The lines usually include short necklines snapped to each dog’s collar, just to keep the dogs in proper position. Dogs may be omitted from the teams on subsequent days, but none may be added.
Organised dogsled racing orginates from the city of Nome, Alaska, back in 1908. Sleddog Racing, is a winter dog sport involving the timed competition of teams of sleddogs that pull a sled with the dog driver or musher standing on the runners. The team completing the marked course in the least time is judged the winner. Driving sled dogs has become a popular winter recreation and sport in North America and Europe; sled dogs are now found even in such unlikely places as Australia and Patagonia.
Sprint races frequently are two or three-day events with heats run on successive days with the same dogs over the same course. Mid-distance races are either heat races of 14 to 80 miles per day, or continuous races of 100 to 200 miles usually. Generally the teams start one after another in equal time intervals, competing against the clock rather than directly against one another.
Races are categorised not only by distance, but by the maximum number of dogs allowed in each team. The most usual categories are four-dog, six-dog, eight-dog, ten-dog, and unlimited (also called open), although other team size categories can be found.