Dr. Ernie Ward explains why small dogs tend to live longer than big dogs. For more from Dr. Ward, find him on Facebook or at www.drernieward.com.
As a practicing veterinarian of over twenty years, I’ve been nagged by an obvious and seemingly unanswerable question: why do small dogs live longer than large dogs? For years it’s been widely accepted and understood in the pet world that tiny teacup poodles will live ten or more years longer than a Great Dane. They’re both dogs, share the same basic DNA, eat the same types of foods, and live in similar homes. Yet one breed lives up to three times longer. Why? New research sheds some light on this issue.
In the April issue of the scientific journal “The American Naturalist,” biologists at Germany’s University of Göttingen explored the relationship between size of dog breeds and life expectancy. Researchers analyzed data on over 56,000 dogs representing 74 breeds that visited North American veterinary teaching hospitals. The scientists found that larger dogs appeared to age at a faster rate than smaller dogs. Interestingly, the research concluded that every increase in 4.4 pounds (2 kg) reduces life expectancy by approximately one month.
Okay, so my observations on small dogs living longer than big dogs were correct. But why?
That has yet to be definitively determined. Lead researcher Cornelia Kraus has been quoted saying that larger dogs’ lives “seem to unwind in fast motion.” Her research found that bigger breeds died more often from cancer than their tinier canine cousins. Kraus speculates that because large breeds grow faster and age quicker than small breeds, that abnormal cell growth found in cancers would be more likely. Another possibility is that larger dogs start aging at an earlier age, thus developing age-related diseases earlier. Kraus also postulated that larger dogs may simply live riskier or more dangerous lifestyles than dogs carried in handbags, thus leading to earlier mortality.
When Kraus and her colleagues plotted each of these three possibilities with the data, she found that the “faster aging” hypothesis was most consistent with her findings.
My own suspicion is that in addition to accelerated cell division and growth, researchers will also discover more genetic abnormalities in large breeds due to fewer breeding pairs and smaller geographic distributions. I also think they’ll find differences in key hormones such as IGF-1 or insulin-like growth factor 1, something scientists have previously suggested. After all, we’ve created these breeds to suit our particular working needs and tastes without regard to their individual longevity. In addition, many giant breed dogs aren’t as popular as more compact canines, especially in the United States. For example, the top three largest breeds in this year’s top 10 American Kennel Club (AKC) breeds list are Labrador and Golden retrievers and German shepherd dogs. Not exactly Great Dane and mastiff-sized canines. In fact, of the large breeds Rottweilers ranked ninth in 2012, Dobermans peaked at 12, Great Danes reached 17, and Mastiffs topped out at 26. All the rest of the most popular breeds are smaller.
So this particular research didn’t exactly answer my question. Yet. Kraus and her colleagues are now pursuing why the death rates are younger in large breeds since they’ve established that it does, in fact, occur.
If you have any questions or concerns, you should always visit or call your veterinarian – they are your best resource to ensure the health and well-being of your pets.
3 Dachshund 12-15 Years
This little sausage dog with the long body and short legs is a playful breed who can be stubborn due to their hunting instincts. They can and will chase animals smaller than they are, and tend to be aggressive towards strangers and other dogs.
The Dachshund has a loud bark and he will use it whenever he feels his home is in danger. This small breed is not great with children, but with socialization from a young age and proper supervision, a Dachshund could be a great family pet.
In general, smaller breeds of dogs will live longer than larger dog breeds. This is due to many factors including their weight, health issues that are common amongst larger dogs, and some other things, as well. Research shows that the average age of dogs that weigh less than 20 pounds is 11 years, while dogs that are more than 90 pounds live for an average of 8 years. With this being said, the average of a dog's lifespan can vary greatly. It depends on how they are being raised, what they are eating, what breed they are, their risk of health issues, and much more.
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Why Do Small Dogs Live Longer?
Researchers Are Studying the Lifespan Inequity of Large and Small Dogs
When it comes to lifespan, researchers have found that size matters. Small dog owners can expect to enjoy several more years with their pets than the owners of large dogs.
It doesn’t seem to make much sense: generally speaking, large mammals, like elephants and whales, tend to live longer than small ones, like mice. So why, then, do small dogs have a longer average life span than the larger breeds?
This phenomenon has baffled scientists for years and was recently the subject of a study published in The American Naturalist. According to the lead researcher, Cornelia Kraus, who is an evolutionary biologist at the University of Göttingen in Germany, large dogs age at an accelerated pace, and “their lives seem to unwind in fast motion.”
Scientists concluded that every 4.4 pounds of body mass reduce a dog’s life expectancy by about a month.
The reason why is still unknown, though Kraus suggests that there are several possibilities, including that larger dogs may succumb to age-related illnesses sooner. Also, larger breeds grow from puppies to adults at an accelerated rate, and this may lead to a higher likelihood of abnormal cell growth and death from cancer.
These findings are just the tip of the iceberg in our understanding of canine lifespans and what determines them. Scientists plan future studies to better explain the link between growth and mortality.
If you've lived with an array of different sized dogs, you may have already figured out that the smaller ones live longer than the larger ones. The difference in the aging process of small dogs versus big dogs is imbalanced throughout their lives, too. Smaller dogs tend to mature faster than their larger counterparts, but after the first few years things even out for awhile until the big dogs take the lead in aging at the five year mark. In her 2007 book "Caring for Your Aging Dog", Janice Borzendowski breaks dog sizes down into small, medium, large and giant to create a chart that tells readers at a glance how old their dogs are in human years. Borzendowski's table starts at five years old, at which point small dogs (20 pounds and lighter, like Chihuahuas and Yorkies) are 36, medium dogs (21 to 50 pounds, cocker spaniels, for example) are 37, large dogs (51 to 90 pounds, such as German shepherds and labrador retrievers) are 40 and giant dogs (91 pounds and bigger like great Danes and mastiffs) are considered to be 42 human years . From there each size ages at the following rates: small dogs age 4 years for every year, medium and large dogs age 5 years for every one year and giant dogs age seven years for every one year.
Slower aging rates for small dogs means their longevity is better than larger dogs. On the average, the life expectancy for small dogs is 14 to 16 years compared to 10 to 14 years for mid-sized dogs and 10 years for large dogs. Giant dogs get the short end of the longevity stick, seldom living longer than 9 years.