Any adult human male should be able to kill a dog in a fight to the death. Even large dogs and wolves.
1. Just about any normal sized man would have a significant size and weight advantage over any dog.
2. Dogs only have one weapon--their mouth. All you have to do is dodge a bite. They have no dangerous claws like other animals do. It's like fighting a one-handed boxer. I think most dudes that get bit do so because they're taken by surprise or they're trying to control the dog without hurting it. But if you don't mind hurting the dog and you're facing off ready to fight, it's not that hard to dodge their mouth.
3. Dogs are stupid. If you put out your left arm as a target the dog will always attack that arm. This means you control his actions. You can either sacrifice your arm to gain opportunity, or you can use the arm to bait him into lunging and then pull it away at the last second and grab the dog with your other hand and slam it on the ground.
4. BJJ works on dogs. There have been cases of perps killing police dogs with a rear naked choke.
Not saying you won't get a little bloody, but you'll win