Working dog

A working dog refers to a dog that performs tasks to assist their human companions. Within this general description, however, there are several ways in which the phrase is used.

To identify any dog that performs any task on a regular basis to assist people. In this context, a dog who helps a rancher manage cattle or who performs tricks for a trainer who receives pay for his act is a working dog, as is an assistance dog. This might be in comparison to a companion dog, whose purpose is primarily as a pet.
To distinguish between show dogs, who are bred primarily for their appearance in an attempt to match some breed club's detailed description of what such a breed should look like, and working dogs, who are bred primarily for their ability to perform a task. For example, a Border Collie who is a champion show dog is not necessarily good at herding sheep; a Border Collie who is a champion at sheep dog trials might be laughed out of the show ring for his nonstandard appearance.

For some breeds, there are separate registries for tracking the ancestry of working dogs and that of show dogs. For example, in Australia, there are separate registries for working and show Australian Kelpies; the working registry encourages the breeding of any Kelpies with a strong instinct to herd, no matter their appearance or coat color; the show registry encourages breeding only among Kelpies whose ancestors were registered as show dogs and who have only solid-colored coats.

As a catch-all for dog breeds whose original purpose was to perform tasks that do not fit into a more specific category of work. For example, the American Kennel Club uses Working Dogs to describe breeds who were originally bred for jobs other than herding or hunting. Such jobs might include pulling carts, guarding, and so on.