A pit bull mastiff is a hybrid that is part American pit bull terrier and part mastiff. The pit bull mastiff is a large dog. The mixed breed is a popular choice for guard dogs and tends to be healthy.
The American pit bull terrier, American Staffordshire terrier and American bulldog are commonly called pit bulls, even though "pit bull" is not an actual dog breed. There are more than a dozen breeds of mastiff. The bullmastiff, English mastiff, American mastiff and Alpine mastiff are common breeds. Mastiffs make excellent guard dogs, unlike pit bulls, which are sometimes too friendly with strangers.