Dogs belong to Canid family (Canidae).

Dogs first appeared about 40 million years ago, before any other carnivore families like bears or cats.

Carnivores have a pair of teeth similar to blades that are called carnassials. These teeth are like scissors and can slice through skin and muscle.

Thirty five living species are included in Canid family tree. There are three main groups.

1. South American foxes 2. Wolves, including jackals, wolves, coyotes, and dogs 3. Foxes including red fox and his relatives. The dog that we commonly know is closest kin to gray wolf.

There is genetic evidence and fossils that confirm that all dogs are direct descendants of wolves. Skeletons of earliest dogs and their wolf cousins are very hard to find differences.

There are around 400 domestic breeds of dogs and they all belong to same species, Canis familiaris.

Using dogs in fighting has been around for hundreds maybe thousands of years. The Romans, Greeks, Spanish and French used dogs for fighting.

Fighting between all kinds of animals have always been a very popular event. As far back as can be recalled dogs called gladiator were bred for sole purpose of dog fighting.

The British began breeding bulldog for sole reason of dog on dog combat, but they were not first; since this event has been around since day of Roman Empire. The dogs that British used are commonly known today as American Pit Bull Terrier.

The bulldog is well known for being used to manage unruly bulls, and by hunters for helping them in catching and holding wild boars or other big game.

Since, bull dog was so popular for these types of activities sport of bullbaiting became very popular. Bullbaiting was where bulldogs and other larger animals were pitted together.