The Chihuahua is frequently referred to as the world's shortest dog breed. Miracle Milly, a Chihuahua, was the smallest dog ever, standing at 3.8 inches tall, and weighing around one pound. That is significantly smaller than most dog breeds who are usually considered small, like Corgis, Pugs, or French Bulldogs. All of these are typically between ten and twelve inches tall. Even Dachshunds get to be nine inches tall when they are fully grown, which is more than double the size of Miracle Milly. A better comparison for this little Chihuahua is probably an average rat, whose height is around three inches and the weight is just under 1.5 pounds.