Dog

The domestic dog (Canis lupus familiaris and Canis lupus dingo) is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in human history. The word "dog" may also mean the male of a canine species as opposed to the word "bitch" for the female of the species.

http://en.wikipedia.org/wiki/Dog