There are a lot of different opinions out there about what the toughest dog in the world is. Some people might say it's a Rottweiler, because of their size and strength. Others might say it's a Pit Bull, because of their tenacity and power. And still others might say it's a Doberman Pinscher, because of their Intelligence and loyalty. But the truth is, there is no one "toughest" dog in the world. It really depends on what you're looking for in a dog, and what you think makes a dog tough.