By Dr. Becker
When you evaluate species of mammals, it quickly becomes obvious that as a general rule, the bigger the creature, the longer it lives. Elephants in the wild can live well into their 60’s, whereas squirrels only live about six years.
But when you look closer at individual species, this general rule doesn’t always hold true, and dogs are a good example. As any canine enthusiast knows, big dogs have much shorter lifespans than small dogs. The same holds true for mice, horses, and possibly even humans.
Large Breeds Age Quickly and Die Younger
According to a study published in the April issue of the journal American Naturalist1, big dogs die younger primarily because they age quickly. Study authors believe these new findings can help scientists understand the biological links between growth and mortality.
Dogs seem to be a perfect subject for the study, because humans have bred them throughout history to be wildly variable in size. According to LiveScience, the heaviest dog on record was probably an English Mastiff that weighed 343 pounds, while the smallest was a terrier weighing in at under a quarter-pound. There is no other species of mammal with such tremendous size disparity.
Giant breeds live the most abbreviated lives of all dogs. For example the Great Dane has an average life span of about seven years, while a Yorkie can be expected to live 13 to 16 years.
A Big Dog’s Life ‘Unwinds in Fast Motion’
The American Naturalist study took a look at ages of death in 74 breeds and over 56,000 dogs that visited veterinary teaching hospitals.
Researchers learned that large breeds seem to age at faster rates than smaller breeds, and the speed at which the risk of death increases with age is also greater with big dogs. According to study authors, “… large dogs age at an accelerated pace, suggesting that their adult life unwinds in fast motion.” For a dog, every 4.4 pounds of body mass takes about a month off his life.
The researchers next want to look at the growth and health histories of dogs to narrow down the leading causes of death for large breeds. For example, bigger dogs more often acquire cancer, which makes sense when you consider they grow more than small dogs, and cancer is the result of abnormal cell growth. It’s possible that humans have inadvertently selected for characteristics – like rapid growth – that predispose large dogs to cancer.
Other large animals like elephants that have many more cells than smaller creatures, and should therefore also be at greater risk for cancer, have undoubtedly evolved special defense mechanisms against disease. These mechanisms probably developed through natural selection over a very long period of time, whereas most dog breeds have evolved through selection by humans, and over a much shorter period of time.
Evolutionarily speaking, dogs have evolved in the blink of an eye, and protective mechanisms against cancer and other diseases haven’t had time to catch up.
Extending the Lives of Large and Giant Breed Dogs
If you own a large or giant breed dog or are thinking about getting one of the big guys, I hope you’ll watch my interview with Dr. Jeff Bergin.
Dr. Bergin and his partner, Christine, raise and breed Newfoundlands, and in my opinion, they do things the right way. In fact, it’s not unusual for their giant breed dogs to live into their late teens. In the world of Newfies, a 17-year lifespan is almost unheard of.
Some of the wonderful practices Dr. Bergin follows with his Newfies include:
- Feeding exclusively raw diets.
- Breeding for health, first and foremost. Dr. Bergin breeds his dogs only once or twice during the course of their lives, with at least six years between litters. He does not breed dogs with congenital defects, and so far only one of his dogs has had a genetic health issue, a heart problem. (Heart problems, osteosarcoma and hip dysplasia are the most common health challenges for this breed.)
- Performing regular chiropractic adjustments. With large and giant breed dogs, it’s very important to take care of the frame. Dr. Bergin happens to be both a licensed animal chiropractor as well as a human chiropractor. He performs regular manual orthopedic manipulation on all his dogs, from the moment they first stand on their own through the remainder of their lives. This practice is one of the keys to keeping a big dog’s musculoskeletal system from degenerating with age. Dr. Bergin’s dogs are typically fully mobile even at the end of their lives.
- Limiting vaccines and other assaults on the immune system. Dr. Bergin only vaccinates his dogs against rabies, because the law requires it. By strictly limiting the number of vaccines they receive, he helps keep his dogs’ immune systems strong and resilient.
- Insuring Newfie litters go to the right families. Dr. Bergin and Christine perform a mandatory home visit to families interested in their dogs. They won’t release a dog without seeing the new home. They conduct in-depth interviews with prospective owners to insure the puppy will be well taken care of. They also insist on a commitment from prospective owners to feed raw.
For most pet owners, it’s the quality of their dog’s life that is most important. You may have your precious pup with you for eight years or twice that long. By focusing on the three pillars of health – nutrition, maintenance of the frame, and a strong, resilient immune system -- you can insure you’re providing her with everything she needs for an excellent quality of life, however long her life may be.