Meet Meysi, a terrier puppy that just might be the world's smallest dog. At just 2.5 inches tall, 4.7 inches long and weighing just 0.3 pounds, she is about the size of a soda can, according to Barcroft Media. I searched this out for BRANDIE who indicated she wanted the 'cat or dog' that i posted in a 'gif' earlier today. yup, it's just way too cute.