The breed almost became extinct when they were no longer used for farm dogs. Literature indicates more crossing and back-crossing of the Rat Terrier with the Chihuahua, toy Fox Terrier, Daschund, and Corgi created the common breed as we know it today. Teddy Roosevelt who brought his dogs to the White House popularized the breed by coining their name, "rat terrier," when renovations of a building on the White House lawn was rat infested. President Roosevelt's ratters are reported to have killed thousands of rats. Today, Rat Terrier typing is used to distinguish the acceptable size and color of the breed.