Background: Why Pure-Bred Dogs Are in Trouble
The present day Bernese Mountain Dog is a breed that is plagued with numerous health issues that are resulting in an abnormally short lifespan. Cancers, immune mediated disease, allergies, digestive issues, degenerative myelopathy, thyroid issues, and widespread reproductive issues are all significantly prevalent in the breed.
Dog Shows and Purebred Dogs
Every "purebred" dog has roots in the various breeds or types from which it originated. This helps us understand why some purebred dogs have significant health issues and offers a possible solution to help improve the health of the Bernese Mountain Dog. Breeding "purebred" dogs is actually recent history. Based around the development of dog shows societal pressure ensued to breed one pure bred dog to the another dog of the same pure breed only. Up to that point, it was not considered taboo to breed out to another breed to acquire a desired trait, be it physical, temperament, or health related. This is how various breeds have been developed as well as kept healthy over the centuries.
Closed Stud Books
Unfortunately with the advent of dog shows and kennel clubs, it became forbidden to "breed out". When a stud book is "closed" on a breed, it means that no dog will be registered any longer that did not come from registered parents of the same breed. So the day the stud book is closed on a breed is the day that breed can only become more and more inbred. Because there is only a finite number of dogs within any purebred breed, the gene pool is instantly limited when the stud book is closed. With the Bernese Mountain Dog, it does not matter if an American-born dog is bred to a German-born dog, the resulting litter will still be inbred as all Bernese Mountains Dogs are related to some degree.
How We Are Taught to Breed Purebred Dogs
Regardless of the venue, all of us - including us in the project - have been taught to breed for the "individual". Meaning, we each have selected dogs to breed together so we can hopefully be more successful in whatever sport we choose. If we show in conformation, we breed towards traits we individually feel that we would be more successful that ring with—be it size, coat, structure, etc. If we show in agility there may be different traits that are selected. Despite our sport of choice, we all breed or select dogs that enable us as individuals to improve our chances of "winning" ... there is nothing "wrong" with this and of course, we each want to be successful in our chosen venues! But none of us has truly been taught how to breed to preserve our breeds—or Preservation Breeding—that we are breeding thinking about the health of the population of the BMD as a whole vs the individual dogs that we may produce. And that has become a problem for the overall health of purebred dogs. The use of "popular sires" is one very prime example of breeding for the individual vs for the overall health of a population of purebred dogs. We each "know" that no individual dog should be overly bred, but "popular sire syndrome" is very much alive in virtually every breed of dog.
At What Cost?
Combined with the fascination with a pedigree that is full of only dogs of the same breed and breeding as individuals- this may be coming at a significant cost. It only takes a little education about genetics to know that a population of any species that becomes more and more inbred becomes more and more at risk of increased health issues, loss of vitality, and difficulties reproducing. And, as "registered" dogs in most countries mean that only the same breed of dog can be bred together, all purebred dogs are becoming more and more inbred despite the efforts of some very conscientious and ethical breeders who are doing their best to produce healthy dogs. If the Bernese Mountain Dog is to survive, it is critical that we have this shift in thinking and breeding. If we continue to concentrate our efforts to breed what we each individually desire and not breed for increased genetic diversity within the entire Bernese Mountain Dog population, our breed will continue to decline and eventually become so closely inbred, that they become extinct.