4. Kangal

They originated in faraway Turkey and used to be one of the best livestock-guarding dog breeds. In order to protect the animals, Kangals had to fight big, dangerous animals. They are strong, big dogs that can weigh up to 140 pounds. Another thing about them that makes these dogs fantastic for guarding is that they have a high tolerance for pain.

Despite their size and protective instinct, these dogs are some real sweethearts with their families. They are really affectionate and are the perfect therapy dogs or service dogs. Their empathy and intelligence are some of their most prominent traits.

One thing that you have to keep in mind is that if you plan to own such a big breed, you need to take responsibility, and this is not the easiest thing to do. According to some studies, their bite force is equal to 743 PSI. This is the most powerful dog bite in the world.