In terms of height, the smallest dog living is a female Chihuahua called Miracle Milly. It measured 9.65 cm (3.8 inches) tall in February 2013 and is owned by Vanesa Semler of Dorado, Puerto Rico.
At present, Guinness World Records has two main categories for smallest pooches: Smallest dog living (height) and Smallest dog living (length).
Born in December 2011, Miracle Milly weighs roughly 1 pound (half a kilogram) and is popular for often sticking out her tiny tongue when someone takes her picture.
When she was born, Miracle Milly just weighed less than an ounce and fit in a teaspoon. Her mouth was so tiny to nurse from her mother, so she was given milk by her owner every two hours through an eyedropper.