American Mastiff
Calm and quiet animals, American Mastiffs are not particularly active pets, preferring to be indoors more than outdoors. However, it is essential for their health to get regular exercise, usually by walking them on a leash, as they can be too lazy to run on their own in a fenced yard, especially when they get older. Training American Mastiffs is normally not a difficult task compared to other large breeds. They are sensitive and highly intelligent dogs that respond well enough to their master's steady and consistent tone, so there is often no need to raise your voice or hand to them. Nevertheless, they are pets that need to grow up with rules and respect in the home. Otherwise, they can become unruly and troublesome. Though laid-back and easy-going, Mastiffs were bred as guard dogs, which contributes to the American Mastiff's protective instincts. Oftentimes, they will only attack if their owners are in danger, but it is still wise to train them on how to react to strangers that are friendly or those who pose a threat.http://www.dogbreedinfo.com/americanmastiff.htm
