The Border Terrier first appeared in the 18th century and has changed little since. They were used as working terriers in the Scottish Borders hunting foxes which preyed on livestock. Their ancestry is not really known.
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Their appearance was never of great concern to their owners but their ability to go to ground after a fox was, so they were bred to have strong jaws, to be well boned but not heavy and to have a chest with sufficient capacity but narrow enough to allow them to get back out of any earth they entered.