A working dog is a dog used to perform practical tasks, as opposed to pet or companion dogs.
Definitions vary on what a working dog is, they are sometimes described as any dog trained for and employed in meaningful work; other times as any dog whose breed heritage or physical characteristics lend itself to working irrespective of an individual animal's training or employment; and other times again it is used as a synonym for herding dog.[1][2][3]
a dog of suitable breed or training kept for its practical use, such as herding sheep, rather than as a pet or for showing
a dog suitable by size, breeding, or training for useful work (such as draft or herding) especially as distinguished from one suitable primarily for pet, show, or sporting use
A dog trained to work with livestock.