Dog Breeds - the Largest, Smallest, and Heaviest

Dogs vary widely in size. We've seen dogs so small that we're afraid we might accidentally step on them (and we're worried our dogs might think they're rodents, they were that small!). We've seen dogs so huge that they could have been saddled up! Although there are always variations in size even within a breed, here are a few generalized fun facts:

Heaviest Dog Breed

Generally acknowledged as the English Mastiff, these giant dogs can weigh as much as 350 pounds! They aren't considered the tallest breed, but instead sport a stock and muscular build.

Tallest Dog Breed

The Great Dane will probably come to mind as one of the tallest dogs in the world, and they are -- but it's actually the long and lean Irish Wolfhound that is generally considered the tallest breed. Although they don't have the stocky build of the mastiff, Irish Wolfhounds are still big dogs and can weigh up to around 150 pounds. At the shoulder, they stand about 3 feet high... and standing on their long hind legs, they can reach as much as 7 feet high!

Smallest Dog Breed

The tiny Chihuahua is considered the smallest breed. There is a wide range of size in the Chihuahua breed, but the "standard" for these dogs is in the 2 to 6 pound range and an average height of 6 to 9 inches.