Dog

Dogs, colloquially known as "man's best friend", are a subspecies of wolves (given the scientific name Canis lupus familiaris), divided into a multitude of different breeds all capable of interbreeding (though in some cases, physical relations between representatives of two breeds are unlikely or problematic - Chihuahuas and Great Danes, for example). They are one of the most well-known domesticated species, with archaeological and historical records showing that they have lived in a mutually beneficial relationship with humans for upwards of ten thousand years; in Biblical times, they had already been coexisting with humans long enough for it to be regarded as the natural order of things.

It is likely, based on genetic evidence, that the oldest breeds of dog originate in Asia, and that thus the domestic dog originated there; similar research has shown that it is probable that the first settlers of the Americas brought dogs of some sort with them.

Dogs are used for many purposes

• Guarding property and livestock.

• Herding sheep and cattle.

• Tracking by scent, carrying messages, and mountain rescue.

• Pursuing, flushing and retrieving game, and killing vermin.

• Providing assistance to blind and deaf people.

• Military and police duties including guarding, tracking and attacking. In World War II, the Soviet Union attempted to train dogs to place explosive charges under German tanks.

• As a beast of burden, or for drawing sledges and dogcarts.

• As a performing animal. Circus dogs have been trained to dance, ride bicycles and walk the tightrope.

And historically,

• For fighting, now illegal in most places.

• As food. Dog is still considered a delicacy in China, Korea and parts of Africa today.

Today most dogs are kept for companionship only. Stray and feral dogs cause many problems, spreading diseases such as rabies, and attacking people and livestock.