38 Dog Breeds That Require Extra Caution and Understanding

24. Bullmastiff

The Bullmastiff is a cross between a bulldog and a mastiff. They can reach 27 inches tall and weigh up to 100 pounds. In the 19th century, they were used to deter poachers and raised as defenders. They may form close bonds with owners but can become challenging if not properly socialized or trained.