20 Largest Dogs on Earth

English Mastiff
Number one on our list and the biggest dog in the world is the English Mastiff. Initially bred for war, this giant mastiff is one of the most massive and oldest dog breeds in the world. While the mastiff's ancestors were fierce war dogs, the mastiff today has a docile kind-hearted temperament. Mastiffs make fine companions for anyone who can accommodate their great size and doesn’t mind a little drool slung here and there.