A hunting dog is a dog that hunts with or for hunters. There are several different types of hunting dog developed for various tasks and purposes. The major categories of hunting dog include hounds, terriers, cur type dogs, and gun dogs. Further distinctions within these categories can be made, based upon the dog's skills and capabilities. They are usually larger and have a more sensitive smell than normal dogs.
The dog (Canis familiaris or Canis lupus familiaris) is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers. Dogs were the first species to be domesticated over 14,000 years ago, before the development of agriculture. Due to their long association with humans, dogs have gained the ability to thrive on a starch-rich diet that would be inadequate for other canids.
Dogs have been bred for desired behaviors, sensory capabilities, and physical attributes. Dog breeds vary widely in shape, size, and color. They have the same number of bones (with the exception of the tail), powerful jaws that house around 42 teeth, and well-developed senses of smell, hearing, and sight. Compared to humans, dogs possess a superior sense of smell and hearing, but inferior visual acuity. Dogs perform many roles for humans, such as hunting, herding, pulling loads, protection, companionship, therapy, aiding disabled people, and assisting police and the military.
A working animal is an animal, usually domesticated, that is kept by humans and trained to perform tasks. Some are used for their physical strength (e.g. oxen and draft horses) or for transportation (e.g. riding horses and camels), while others are service animals trained to execute certain specialized tasks (e.g. hunting and guide dogs, messenger pigeons, and fishing cormorants). They may also be used for milking or herding. Some, at the end of their working lives, may also be used for meat or leather.
The history of working animals may predate agriculture as dogs were used by hunter-gatherer ancestors; around the world, millions of animals work in relationship with their owners. Domesticated species are often bred for different uses and conditions, especially horses and working dogs. Working animals are usually raised on farms, though some are still captured from the wild, such as dolphins and some Asian elephants.