The world’s unofficial smallest dog is a tiny Terrier that measures 7cm tall, 12cm long and weighs 150g about the size of a hamster. Little Meysi is now three months old and is the size of a coke can. Meysi’s owner is trying to get the pup down in the Guinness World Record for smallest dog, however Meysi has to turn one year old first. Awwww! So cute.