Ear carriage is erect, but can also be tipped, or button, all of which contribute to an intelligent, alert expression. The tail has been traditionally docked to about 2–3 inches, but the bobtail gene is very common in Rat Terriers and can result in a variety of tail lengths. Today, some breeders prefer a natural, undocked tail, which is accepted in the breed standards. The genetic diversity of the Rat Terrier has contributed to the overall health, keen intelligence, and soundness of the breed. Most modern breeds were developed from a few founding dogs and then propagated from a closed gene pool. In contrast, the Rat Terrier has benefited from a long history of refinement with regular outcrosses to bring in useful qualities and genetic variability.
2–3 inches,
2–3 inches,