Why Do Small Dogs Live Longer?

You dont necessarily need a working knowledge of evolutionary theory to know that in the animal kingdom, larger beasts tend to live longer than smaller ones.

Professor Elgar says the answer to the puzzle of canine lifespans can be found in data that charts the schedule of a species rate of ageing. Professor Elgar says that a larger dog, because of its size, may put more strain on its physiological processes, meaning they tend to wear out more quickly.

Why dogs buck the trend creates a puzzle, says evolutionary biologist Professor Mark Elgar of the University of Melbournes School of Biosciences. Professor Elgar says the answer to the puzzle of canine lifespans can be found in data that charts the schedule of a species rate of ageing.

Why do small dogs have a longer lifespan?

A millennia of domestication and breeding means that dog breeds can vary in body size by up to 50 times. Professor Elgar says that the research comparing size and age-related mortality in dogs shows that larger dogs die younger because they age significantly faster than smaller dogs.

Is it true that smaller dogs live longer?

The larger the dog, the shorter their life expectancy. A large dog like a Saint Bernard will have a lifespan of between five to eight years, while smaller breeds can generally live as long as 12 to 15 years.

Can small dogs live 20 years?

The smaller breeds of dogs tend to live the longest. Yorkshire terriers, Chihuahuas, Dachshunds, Toy Poodles and Lhasa Apsos are the breeds who typically live the longest with these averaging a lifespan of up to 20 years. … Some of the longest living dogs have been known to live upwards of 20, even 25 years.

Which small dog breed lives the longest?

Chihuahua. The chihuahua is one of the longest-lived dog breeds. Many survive past 15 years, with some living as long as 20 years. Even tiny dogs require plenty of exercise, mental stimulation, and training.

The issue of body size and lifespan is a fascinating topic in biology. Its strange that across species, at least in mammals, large-bodied animals live longer than small-sized animals. For example, elephants live a lot longer than mice. The theory is that

For example, boxers are big dogs, but their higher cancer rates may result in a shorter lifespan.

We often think of our dogs as family, and the hope is to have them live with us as long as possible. Unfortunately, the life expectancy of a dog is much shorter than it is for a person. Still, some dogs are known to live longer than others. Small dogs in general have a longer lifespan than larger dogs, but many factors play into how long you can expect your dog to live.

The overall health of a pet, coupled with the diseases that certain dog breeds are predisposed to, will affect life expectancy. Additionally, the lifestyle a specific dog lives, the nutrition it receives, and preventative measures that its owner takes to limit infectious diseases and parasitic diseases (i.e. transmitted by mosquitos, fleas, and ticks) can all play roles in how long a dog may live.

If a dog is born with a congenital issue or develops a disease impacting organs and body system functions, life expectancy may be cut short. Most small dog breeds are expected to live into the double digits, but there’s no way to guarantee this. Luxating patellas, intervertebral disc disease (IVDD) , mitral valve disease, tracheal collapse, and pancreatitis are common issues that small dogs may be born with or develop throughout their life.

These health problems may contribute to a shortened life expectancy depending on the severity of them and how well they are managed. Feeding a well-balanced diet, following your veterinarian’s vaccination recommendations, getting regular health check-ups for your dog, and administering regular parasite preventatives can all contribute to your dog leading a long, healthy life. The Spruce Pets uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles.

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When it comes to the lifespan of dogs, researchers have found that size matters. Owners of small dogs can expect to enjoy several more years with their pets than the owners of large dogs.

Canis familiaris, aka the domestic dog, is a species with a huge size range when it comes to its breeds . Cornelia Kraus, an evolutionary biologist at the University of Gttingen in Germany, was the lead researcher of a major study of 74 breeds and more than 56,000 dogs seen in North American veterinary teaching hospitals.

Kraus reported that large dogs age at an accelerated pace, and their lives seem to unwind in fast motion. One possibility Kraus suggests is that large breeds grow faster, so they may be more likely than small dogs to also experience the abnormal cell growth seen in cancer. A researcher at the University of Washington, Dr. Silvan Urfer, conducted a large study , collecting data on 169,000 dogs who died or were euthanized within a three-year period at U.S. veterinary clinics.

In the Journal of the American Animal Hospital Association , Dr. Urfer reported when comparing two dogs with all other factors being equal, that he found annual dental cleanings conducted by a veterinarian reducing risk of death by almost 20 percent. New research from the WALTHAM Centre for Pet Nutrition and the University of Liverpool revealed overweight and obese dogs are more likely to have shorter lives than those at ideal body weight. Study co-author and Professor of Small Animal Medicine at the University of Liverpool Alex German said, Owners are often unaware that their dog is overweight, and many may not realize the impact that it can have on health.

Factors That Affect Life Expectancy in Dogs

Not all small dogs will live the same amount of time. This is due to various factors. The overall health of a pet, coupled with the diseases that certain dog breeds are predisposed to, will affect life expectancy. Additionally, the lifestyle a specific dog lives, the nutrition it receives, and preventative measures that its owner takes to limit infectious diseases and parasitic diseases (i.e. transmitted by mosquitos, fleas, and ticks) can all play roles in how long a dog may live.If a dog is born with a congenital issue or develops a disease impacting organs and body system functions, life expectancy may be cut short. Indoor dogs that are spayed or neutered are less likely to be hit by a car and be injured or die, so regardless of breed, lifestyle may also play a role in how long a dog lives.Finally, if proper nutrition is not provided or a dog is exposed to pathogens without being vaccinated or properly protected with regular preventative medications, life expectancy can be negatively influenced. Not all causes of death are natural or due to old age, so the preventive care dog owners can play a big role in determining how long their dog may live.

Common Health Problems of Small Dogs

Small dogs develop many of the same health problems that large dogs do, but small dog breeds are more likely than large breed dogs to develop specific issues. Luxating patellas, intervertebral disc disease (IVDD), mitral valve disease, tracheal collapse, and pancreatitis are common issues that small dogs may be born with or develop throughout their life. For example, dachshunds are especially prone to dying from diseases such as IVDD, and Maltese and Chihuahuas are likely to pass from heart disease, like mitral valve disease. These health problems may contribute to a shortened life expectancy depending on the severity of them and how well they are managed. Other health problems can also decrease a dog’s quality of life and therefore lead to euthanasia but aren’t necessarily the cause of death in a dog.

Human Vs. Dog Years

It’s important to understand what it really means when we say how old our dogs are. Dogs and people age at very different rates. When dogs reach one year old, veterinarians estimate they have matured as much as people have when they reach 15 years old. The second year in a dog’s life equates to about another 9 years for a human. And after that, the aging process in dogs varies based on their age and size.

Size Matters

Although large mammals tend to live the longest, small body size within a species is associated with longer life and slower aging. Canis familiaris, aka the domestic dog, is a species with a huge size range when it comes to its breeds.Cornelia Kraus, an evolutionary biologist at the University of Göttingen in Germany, was the lead researcher of a major study of 74 breeds and more than 56,000 dogs seen in North American veterinary teaching hospitals. Kraus reported that large dogs age at an accelerated pace, and “their lives seem to unwind in fast motion.”In the study, large breeds died more often from cancer than small breeds. Why? One possibility Kraus suggests is that large breeds grow faster, so they may be more likely than small dogs to also experience the abnormal cell growth seen in cancer. Or because they age more quickly, large dogs may succumb to age-related illnesses sooner.A researcher at the University of Washington, Dr. Silvan Urfer, conducted a large study, collecting data on 169,000 dogs who died or were euthanized within a three-year period at U.S. veterinary clinics. He found a correlation between the breed of the dogs and their age at death. For example, among giant breeds, Great Pyrenees lived longer (11.55 years) than Great Danes (9.63 years).In Dr. Urfer’s study, small dogs had a longer median lifespan at 14.95 years, medium-size dogs lived an average of 13.86 years, and large dogs lived 13.38 years. The dog’s body size was the most important variable in predicting lifespan, more important than whether or not the dog was purebred.

Breeding

Another factor researchers have studied is the size of the breeding population, and its impact on health and longevity. One study of companion dogs “did not find significant differences in lifespan between purebred and mixed breed dogs; however, breeds with larger effective population sizes and/or lower inbreeding coefficients had median survival times 3-6 months longer than breeds with smaller effective population sizes or higher inbreeding coefficients, indicating that these measures of genetic diversity may be affecting breed lifespans.”

Dental Health

In the Journal of the American Animal Hospital Association, Dr. Urfer reported when comparing two dogs with all other factors being equal, that he found annual dental cleanings conducted by a veterinarian reducing risk of death by almost 20 percent. Dr. Urfer pointed out that there could be a direct association between good dental health and good general health, but it might also be that dog owners who take good care of their dog’s teeth would also be more likely to provide preventive and veterinary care that contribute to longevity.

Weight

New research from the WALTHAM Centre for Pet Nutrition and the University of Liverpool revealed overweight and obese dogs are more likely to have shorter lives than those at ideal body weight. Study co-author and Professor of Small Animal Medicine at the University of Liverpool Alex German said, “Owners are often unaware that their dog is overweight, and many may not realize the impact that it can have on health. What they may not know is that, if their beloved pet is too heavy, they are more likely to suffer from other problems such as joint disease, breathing issues, and certain types of cancer, as well as having a poorer quality of life. These health and wellbeing issues can significantly impact how long they live.”One study that focused on 12 specific breeds found the effect on lifespan of extra weight on the smallest dogs, such as Yorkshire Terriers, was even greater (overweight: 13.7 years, normal: 16.2 years) than the effect on larger dogs such as German Shepherd Dogs.

Cognitive Development

Another study asked a very interesting question about dog cognition. Since large dogs have a speedier growth rate and physiological pace of aging than small dogs, do they also have a faster pace of cognitive development? Researchers measured cognitive development and aging in more than 4,000 dogs from 66 breeds using nine memory and decision-making tasks. They found that all breeds, regardless of size or lifespan, tended to follow the same speed of cognitive aging, no matter the size of the dog.

The Search Goes On

These findings are just the tip of the iceberg in our understanding of canine lifespans and what determines them. A grant from the National Institute on Aging is funding a project, called the Dog Aging Project, to explore the biological and environmental determinants of aging in dogs.The project is based at the University of Washington and Texas A&M College of Veterinary Medicine and Biomedical Sciences. Nearly 30,000 dogs and their owners from across the U.S. are participating. Scientists and research veterinarians from 20 research institutions and veterinary teaching hospitals are following the health and aging process of these dogs for 10 years or more to understand how genes, lifestyle, and environment influence aging.According to the project website, “This information will be used to gain insights that will increase our ability to prevent, diagnose, and treat age-related diseases, thereby helping our dogs, and by extension, ourselves, live longer, healthier lives.”