Herding dog

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An Australian Kelpie backing sheep.
A Koolie working with sheep.
Sheepdog transported with livestock in Fairlie, New Zealand

A herding dog, also known as a stock dog or working dog, is a type of dog that either has been trained in herding livestock or belongs to one of the breeds that were developed for herding. A dog specifically trained to herd sheep is known as a sheep dog or shepherd dog, and one trained to herd cattle is known as a cattle dog or cow dog.