Bernese Mountain Dog is an internationally recognized breed originating in Switzerland. Throughout history served Swiss farmers in performing everyday tasks related to agriculture but also to guard and defend against predators. Over time, the skills and the aggressiveness of the breed has been less and less necessary. Selecting individuals during the twentieth century, breed was developed in the family dog that we know today. Many positive features are related with Bernese Mountain dog. Higher incidence of hereditary disease which are characteristic not only for this breed, but also the remaining medium and large breeds. The most common diseases are: von Willebrand's disease, hip dysplasia, elbow dysplasia, osteochondrosis, progressive retinal atrophy and panostitis. Significant role in the development of these diseases have genetic factors and environmental factors. In order to reduce their prevalence in breeding an early recognition of the disorder is systematic monitoring of health. Using different methods of selection and improvement of diagnostic techniques using molecular genetic tests and Genome Wide Association Studies can be greatly reduced as the frequency of undesirable genes, and detecting potential carriers of undesirable forms.