Boo

Boo Boo is the world's smallest dog by height, according to the Guinness Book of World Records.^[1][2]

Boo Boo faces competition from Milly,^[2] another Chihuahua and Beyonce,^[3][4] a Dachshund-Chihuahua mix but they can not be considered until they are one year old. Boo Boo weathered a challenge from Scooter, a Maltese^[5][6]