Weight pulling is a dog sport  involving a dog pulling a cart or sled loaded with weight a short distance across grass, carpet, or snow. Many breeds participate in this sport, with dogs being separated into classes by weight. Sled dog and bull breeds excel within their respective weight classes, having been historically bred to pull sleds and plows, respectively.

The dog is hitched to the sled with a specially constructed harness designed to spread the weight and minimize the chance of injury. Such as those show below.

 

Dog weight pulling competitions are sanctioned by various non-profit organizations. In North America the International Sled Dog Racing Association has sanctioned contests in association with their races. The International weight pulling association was organized in 1984 to promote the heritage of the working dog.