Tracing the history of the sled dog; Sled Dogs, by Brigid Casey and Wendy Haugh. New York: Dodd, Mead & Co. 80 pp.

Almost every youngster is familiar with domesticated dogs. But most often they see a dog as a playmate or a pet. They don't know that many dogs, from Collies to Terriers, are considered working or sporting breeds, that is, dogs that were bred in past years to assist man in herding animals or transporting supplies.

Brigid Casey and Wendy Haugh have taken a very close look at working sled dogs to produce a book that will both inform and captivate young dog lovers.

They begin with the early ancestors of today's Arctic dogs and trace their history, focusing primarily on four breeds, the Eskimo dog, the Alaskan Malamute , the Samoyed, and the Siberian husky.

An abundance of old prints, new and old photographs, and clear diagrams help the authors tell about these strong yet compact dogs, capable of pulling a sled at a rate of more than 20 miles an hour over snow and ice for long stretches of time. Readers may be surprised to learn how the teams are driven with the musher using voice commands only.

Included in the book are diagrams of the methods of harnessing dogs; the importance of a good lead dog that must lead on despite driving snow or lost trails; stories of successful polar expeditions using dogs vs. ponies. Especially interesting is the section devoted to the currently popular sport of dog sled racing in the United States and Canada, a sport that began in the early 1900s.

This is a good resource book with high interest value for young readers - particularly ones who may prefer factual books over fiction.