In England terrier type dogs and mastiff type dogs have along history. Many terriers were used to kill vermin that might destroy crops, and spread diseases. Then the development of sports such as rat or badger baiting added to the breeds hisotry. Mastiff dogs were used as war or guardian dogs and served utilitarian purposes, such as farm work. One such dog was the Alaunt that were thought to have been brought over by the Celts. These dogs helped farmers bring bulls in from the field for breeding, slaughter, or castration. The dogs generally known as bulldogs, would protect the farmer if the bull tried to gore him by biting the bull on the nose until it submitted, despite any injurys the dog may have sustained. These traits led to the cruel sport of bull baiting, and bear baiting. By 1835 bull and bear baiting were stopped by the Parliament as cruel and that's when dog fighting began to blossom. Because bulldogs seemed uninterested in dog fighting, they were crossed with English terriers. They were also bred to be level-headed and nonaggressive during a fight so that if a referee that was unacquainted with the dog could go in the ring and pick the dog up while it was engaged in a fight and take it to it's owner to carry it out of the ring. If a referee was bitten by the dog, then the dog was put to death. As a result, these type of dogs were kept at the home of gambling men. In the mid 1800's immigration from Ireland and England brought many of these dogs to the U.S. where they were bred to be larger and stronger. The resulting breed was called the American Pitbull Terrier. Pitbull is a term commonly used to described several types of dogs with similar physical characteristics, such as the American Bulldog, American Staffordshire Terrier, Staffordshire Bull Terrier, Perro de Presa Canario, Cane Corso, Dogo Argentino, and the Alano Espanol. The way the word Pitbull is used in the media is often not clearly defined and never really descriptive of the specific breed. Pitbulls are often used for dogfights because of their aggressiveness, tenacity, high tolerance for pain, gameness, and availability. Although dogfighting is illegal in the U.S., it is still done for entertainment and gambling purposes. Dogfighting laws differ in some states, but most state have some type of laws against dogfighting. Most people who have Pitbulls involve them in sports such as Schutzhund, agility, weight pulling, and obedience competitions. A study published in the Journal of the American Veterinary Medicine Association in September 2000 reported that in 20 years of study (1979 to 1999) Pitbull type dogs and Rottweilers were involved in one half of approximately 300 dog bite related fatalities in the U.S, and another study of American and Canadian dog bite related fatalities from September 1982 to November 2006 produced similar results. Pitbulls still remain one of America's most loved breeds because of their loyalty and devotion to their family. Some work in hospitals as certified therapy dogs, and some have even saved lives, but because of the breeds fighting history and the coverage of the media in dog related incidents, Pitbulls are banned or restricted to a high degree in some countries and cities.