Rat Terrier
The Rat Terrier is an American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 dog breed
Dog breed
Dog breeds are groups of closely related and visibly similar domestic dogs, which are all of the subspecies Canis lupus familiaris, having characteristic traits that are selected and maintained by humans, bred from a known foundation stock....

 with a rich and varied background as an all-around farm dog and hunting companion. Traditionally more of a type
Dog type
Dog types are broad categories of dogs based on function, with dogs identified primarily by specific function or style of work rather than by lineage or appearance....

 than a breed
A breed is a group of domestic animals or plants with a homogeneous appearance, behavior, and other characteristics that distinguish it from other animals or plants of the same species. Despite the centrality of the idea of "breeds" to animal husbandry, there is no scientifically accepted...

, they share much ancestry with the tough little mixed-breed dogs known as feist
Feist (dog)
A Feist is a type of small hunting dog, developed via crossbreeding of various other hunting breeds in the rural southern United States.- Description :...

s. Several private associations have maintained Rat Terrier registries for some decades, but more recently there have been movements to obtain breed recognition by the major canine organizations.