Bullmastiff. The Bullmastiff dog breed is a firm and fearless family guardian. ... Called the “silent watchdog,” this breed is nonetheless so mellow that they make great apartment dogs. They have short, easy-care coats, but beware: These dogs are droolers. Weight: 100 to 130 pounds Height: 24 to 27 inches at the shoulder

Bullmastiffs are gentle and affectionate with family members. Their generally calm, easy-going natures make them good dogs for families with reasonably well-behaved children. However, the bullmastiff's laid-back attitude with family members is likely to change when a stranger enters the picture. These dogs tend to be quite suspicious of people outside the family. For all his family-oriented loyalty, the bullmastiff is no pushover. He can be an independent thinker, which can make training a challenge. He also may be less tolerant of a family's animal members than of its human members. Caution may be in order if you're thinking of adding a bullmastiff to your menagerie.

Common health problems in this breed include cancer, hip and elbow dysplasia, torn anterior cruciate ligaments, bloat, subaortic stenosis, skin and coat problems, hypothyroidism, and entropion. Hip Dysplasia: This is a heritable condition in which the thighbone doesn't fit snugly into the hip joint.