Sealyham terrier is a strong, white, short-legged dog with a long head, powerful jaws, and big teeth. It is good at catching rats and mice. This dog stands about 11 inches (28 centimeters) high and weighs 23 to 25 pounds (10 to 11 kilograms). The Sealyham terrier was first bred about 1850 at Sealyham, an estate in Pembrokeshire, Wales. It was once used in Wales to frighten badgers, foxes, and otters from their burrows. If necessary, it would go into the burrow and drag the animal out.