Great Britain and Ireland are birthplace of most terrier breeds. The terrier breeds were used to control rabbits, foxes and rats. Some strong and big breeds are used to control badgers. The word terrier is derived from the Middle French terre, which got its name from terra, a Latin word meaning earth. The Kerry Blue Terrier and Airedale are most effective in controlling in river rats and otters. The terriers were bred as per the hunting needs of the locality. The new breeds were developed by mating Terriers with hunting dogs and fighting dogs. Sometimes, terriers were crossed among themselves to raise new breed. In the mid-19th century, the use of terriers which were bred for hunting decreased thus leading to the breeding of more refined breeds. These days terriers breed are used as pets and not for hunting. It is learnt that terriers were crossed with hounds in the 18th century in order to make them more powerful and improve their hunting skills. Terriers were also used for dog fighting sports. The studies of the genes of terriers have revealed that most of them are in the "modern/hunting" genetic cluster of dog breeds.
