About 6-8 years. The average lifespan of the Bernese has decreased in recent years from 10-12 yrs to 6-8 yrs. The BMD Club of America did a health survey in 2000 with 1,322 dogs. The average age of death was 7.2 yrs. Cancer is unfortunately a very large part of the Berner world and many Berners die young. One source states "I know of several that died of cancer at 3-4 yrs old and one that died two days before his 2nd birthday. The BMD Club of America is aggressively researching this cancer issue! We must see if we can end this sad situation."
The Bernese Mountain Dog is a very hardy breed, but beware of hip and elbow dysplasia. Also prone to cancer, bloat and eyelid problems.