Famous and fictional Chihuahuas, worlds smallest dog.

Boo Boo, a 4-inch (10.16 cm) tall long-haired female chihuahua who weighs only 1 1/2 lbs. (675 g) was named the World's Smallest Living Dog by the Guinness Book of World Records in May 2007. Records are determined by height from toe to shoulder. Boo Boo, who weighed only one ounce at birth, succeeded another chihuahua named Ducky who stood 4.9 inches. (Ducky in turn had succeeded Danka Kordak of Slovakia, yet another Chihuahua who measured 5.4 inches tall.)