Cancer is the leading cause of death for dogs in general, but Bernese Mountain Dogs have a much higher rate of fatal cancer than other breeds; in both U.S./Canada and UK surveys, nearly half of Bernese Mountain Dogs die of cancer, compared to about 27% of all dogs. Bernese Mountain Dogs are killed by many types of cancer, including malignant histiocytosis, mast cell tumor, lymphosarcoma, fibrosarcoma, and osteosarcoma. Inherited medical problems that a Bernese Mountain Dog may face include malignant histiocytosis, hypomyelinogenesis, progressive retinal atrophy, and possibly cataracts and hypoadrenocorticism. The breed is also prone to histiocytic sarcoma, a cancer of the muscle tissue that is very aggressive, and hereditary eye diseases that are common among larger dogs. A four-year-old Bernese with lymphoma named Dylan was one of the first dogs to receive chemotherapy at the Virginia-Maryland Regional College of Veterinary Medicine, and it was successful.
Bernese Mountain Dogs have an unusually high mortality due to musculoskeletal causes. Arthritis, hip dysplasia, and cruciate ligament rupture were reported as the cause of death in 6% of Bernese Mountain Dogs in the UK study; for comparison, mortality due to musculoskeletal ailments was reported to be less than 2% for pure-bred dogs in general. Owners of Bernese Mountain Dogs are nearly three times as likely as owners of other breeds to report musculoskeletal problems in their dogs; the most commonly reported being cruciate ligament rupture, arthritis (especially in shoulders and elbows), hip dysplasia, and osteochondritis. The age at onset for musculoskeletal problems is also unusually low. In the U.S./Canada study, 11% of living dogs had arthritis at an average age of 4.3 years. Most other common, non-musculoskeletal morbidity issues strike Berners at rates similar to other breeds. Prospective Bernese Mountain Dog owners should be prepared to cope with a large dog that may have mobility problems at a young age. Options to help mobility-impaired dogs may include ramps for car or house access, lifting harnesses and slings, and dog wheelchairs (ex: Walkin` Wheels). Comfortable bedding may help alleviate joint pain. Due to these common medical issues, owners of Bernese Mountain Dogs should make sure that their dogs receive OFA and CERF certificates.