The Bernese Mountain Dog is a large-sized breed of dog, one of the four breeds of Sennenhund-type dogs from the Swiss Alps. Bred from crosses of Mastiffs and guard-type breeds, Bernese Mountain Dogs were brought to Switzerland by the Romans 2,000 years ago.

Most Bernese Mountain Dogs are peaceful and sociable with other animals. But some Bernese males are aggressive toward other male dogs. Responsive to obedience training in a slow, good-natured way, this sensitive breed should be handled kindly, with much praise and encouragement.

The more serious ailments affecting this breed include canine hip dysplasia (CHD), elbow dysplsia, gastric torsion, and mast cell tumor. A lot of care should be taken to prevent heat stroke. DNA, cardiac, hip, eye, and elbow tests are advised for the Bernese Mountain Dog, which has an average lifespan of 6 to 9 years.