Why does a small dog live longer than a large one?


The average life of dogs varies considerably taking into account the breed of the dog and the size it has. There is a popular belief that one year of the human being is equal to seven years of a dog. But this statement is incorrect, since to know how many years a dog can live, its size and, therefore, its breed must be taken into account.

To determine which dog breeds have the longest and shortest life expectancy, Wall Street analyzed the average age of death of 148 dog breeds from a research published by the National Center for Biotechnology Information.

The 40 breeds of dogs that have a shorter life expectancy live on average a little less than 10 years, more than two years less than the average lifespan of all dogs. On the other hand, the average life expectancy of breeds on the list of dogs that live for many years is 14.3 years, two years longer than the average life.

In mammals, large body animals live longer than small animals. For example, elephants live much longer than mice.

In the animal kingdom, size usually equals longevity: elephants and whales can live about 70 years, a common mouse, two. In the world of dogs the opposite happens

While a giant-sized dog will be considered old at six, a large one at eight and medium-sized at ten, some small-sized dogs will begin old age from the age of twelve or thirteen.

Many hypotheses have emerged to explain the causes, including:

A hypothesis that is evaluated comes from reviewing the size of the dogs in relation to the size of their heart. While large dogs have a bigger heart than small dogs, it is in proportion to the size of the dog where the difference lies.

Apparently large dogs have a much smaller heart than small dogs in relation to their body. Therefore this would make a double effort to be able to pump the adequate amount of blood throughout the animal's body, which would lead to a faster deterioration.

  • Predisposition to serious diseases

The predisposition to diseases is another element that ends up shortening the life of dogs. For example, giant-sized dogs tend to suffer more from joint and muscle problems than small dogs.

  • Similarly, diseases such as cancer are much more frequent in large dogs, especially those that suffer in the bones (osteosarcoma).

  • The proportion of the size

The ancestors of the dogs, the wolves, have the size and weight of a large dog, and in the case of some sub-species, those of a giant dog. However, wolves can live on average 15 years. Dogs of the same size and weight hardly reach those ages, which has led to suggesting that there is an ideal size in dogs.

The problem with this is that dogs, and especially breeds, have been created by man following patterns that are normally aesthetic.

A few years ago, a large study was published using mortality data from thousands of dogs of 74 breeds, testing three hypotheses: Large dogs may die younger than small dogs due to an early onset of senescence, (2) A larger minimum mortality risk, or (3) a higher aging rate.

The conclusion of their study is that aging begins at about the same age in small and large breeds, but large breeds age faster. We do not have a clear understanding of the underlying mechanism for faster aging in dogs.

Researchers Josh Winward and Alex Ionescu, from Colgate University, collected 80 tissue samples from puppies and old, freshly killed dogs, large and small breeds. They isolated cells from these remains and cultured them in the laboratory to analyze them.

They found that in the cells of adult dogs of both types, energy and free radical production was balanced. In those of bulky young, things changed: the rate of oxygen free radicals skyrocketed, and antioxidants could not stop them. This happens because puppies of large breeds have fast metabolisms that consume much more energy than small specimens. Such an imbalance causes cellular damage that manifests itself in a few years and shortens the life of animals.

Oxygen free radicals arise as a waste from the process by which cells obtain energy from food. They are molecules that have lost electrons and try to recover them by "stealing them" from the body's cells, damaging them ("oxidizing them") in the attempt. The body generates antioxidant molecules that neutralize these pernicious agents, but the more energy an organism produces, the more free radicals escape to harm.

Race type: average longevity in years

Alaskan Malamute: 10 - 12

Old English Shepherd: 12 - 13

Basset Hound or Hush puppies: 11 - 12

Bearded Collie or Bearded Collie: 12 - 13

Beauceron or Beauce pastor: 8 - 10

Bichon Frize: 12 - 13

Maltese Bichon: 12 - 15

Border Collie: 12 - 13

Border Terrier: 14 - 15

Boston Terrier: 12 - 15

German shorthaired pointer: 12 - 14

Bull Terrier: 10 - 14

English Bull Terrier: 11 - 13

Miniature Bull Terrier: 12 - 14

American Bulldog: 10-15

French Bulldog: 12 - 15

English Bulldog: 8 - 12

Bullmastiff: 8 - 10

Cane Corsican or Italian Mastiff: 10 - 12

Dwarf Poodle: 12 - 20

Medium Poodle: 8 - 12

Chihuahua: 10 - 20

Chow Chow: 9 - 12

English Cocker Spaniel: 12 - 15

Long-haired or rough collie collie: 14 - 16

Short-haired collie or smooth collie: 10 - 14

Pembroke Welsh Corgi: 12 - 15

Coton de Tulear: 12 - 14

Dachshund: 12 - 14

Doberman: 10 - 13

Dogue de Bordeaux: 10 - 12

Fox Terrier: 12 - 14

English Greyhound: 10 - 13

Afghan greyhound: 10 - 14

Russian Greyhound (Borzoi): 11 - 14

Persian Greyhound (Saluki): 10 - 14

Giant of the Pyrenees: 11 - 15

Golden Retriever: 10-15

Great Dane: 7 - 10

Siberian Husky: 12 - 15

Kerry Blue Terrier: 12 - 15

Labrador Retriever: 10 - 13

Lakeland Terrier: 14 - 15

Lhasa apso: 10 - 20

Manchester Terrier: 15 - 16

English Mastiff or Mastiff: 8 - 12

Neapolitan Mastiff: 8 - 10

Münsterländer: 12 - 14

Papillon: 12 - 15

German Shepherd: 9 - 13

Australian Shepherd: 12-18

Belgian Shepherd: 10 - 12

Croatian shepherd: 10 - 12

Brie Pastor: 8 - 10

Shetland Shepherd: 12 - 13

Pekingese: 11 - 15

Drenthe Retriever: 12 - 14

Spanish Water Dog: 10 - 14

Newfoundland dog: 8 - 10

Czechoslovakian wolf dog: 14 - 15

Dwarf Pinscher: 12 - 14

American Pit Bull Terrier: 8 - 15

Pomeranian: 12 - 16

Presa Canario or Dogo Canario: 10 - 12

Chesapeake Bay Retriever: 10 - 13

Nova Scotia Retriever: 12 - 15

Rhodesian Ridgeback: 10 - 14

Rottweiler: 8 - 10

Samoyed: 12 - 14

San Bernardo: 8 - 10

Dwarf or Minitarua Schnauzer: 12 - 14

Standard Schnauzer: 12 - 14

Giant Schnauzer: 11 - 13

Chinese Shar Pei: 7 - 10

Shetland: 12 - 14

Shih Tzu: 10-20

Shiba Inu: 12 - 15

Silky Terrier: 14 - 16

Breton Spaniel: 12 - 14

English Scout Spaniel: 10 - 14

Pomeranian Spitz: 12 - 16

Staffordshire bull terrier: 12 - 14

Dachshund (dachshund): 10 - 12

West Highland White Terrier (Westy): 12 - 14

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New research explains why small dogs tend to live longer than large dogs. When it comes to life expectancy, studies have discovered that size matters, small dog owners can enjoy more years with their pets than large dogs.

In biology it is amazing how body size can influence the longevity of any mammal. In general, animals in a body with large dimensions live longer than small animals, an elephant, for example, lives much more than a rabbit.

Life expectancy theory suggests that large animals have a slower metabolism than small animals, and that a rapid metabolism significantly shortens the animal's life.

However, there are always exceptions that confirm the rule, small dogs live longer than large ones. One of the explanations is that large dogs grow faster than their smaller peers because they reach a larger size in a short time. That is, rapid growth could be related to accelerated aging and the probability of disease.

Canine graphic age and weight ratio. Image: Viralplus

The study proposes a logical explanation that makes large dogs have a shorter life than small dogs. The graph data comes from 32 different dog breeds. It is observed that some large races, around 40 and 50 kilograms, live between 12 and 13 years on average while some other races of the same size live only 8 or 9 years.

3. Big dogs have a small heart.

Another possible theory may be in the difference between the body mass of a large dog and the size of its heart, since in proportion, large dogs have a smaller heart than small dogs. It may be that this causes the hearts of large dogs to live less because they suffer more and wear out before that of smaller dogs.

4. The fault could be the oxygen free radicals.

Now speaking scientifically, according to current research by a team of students at Colgate University, in Hamilton, in New York.

Oxygen free radicals appear as a waste of the process by which cells obtain energy from food. They are molecules that have lost electrons and try to recover them by removing them from other cells in the body, "oxidizing" them in the attempt. The body generates "antioxidant" molecules that neutralize them, but the more energy an organism produces, the more free radicals escape to harm.

This metabolic process seems to be one of those responsible for the aging and deterioration of the body, and could explain why large dogs live less and usually die earlier than smaller ones.

This happens because puppies of large breeds have fast metabolisms that consume much more energy than small dogs. This imbalance causes damage to the cells that will appear in a few years and shorten the life expectancy of large dogs.

We have left you some ideas of why the big ones can live longer than the little ones. We await your comments if you believe any more theory. And remember that you can find all kinds of custom collars for your dogs on our Dog Collars website.

Life expectancy of dogs

The life expectancy of a dog It is that average time that is expected to live. A curious fact that has been observed is that the older a dog is, the lower the age at which he will die.

For example, Great Dane lives approximately 7 years, however, the death of a poodle is estimated at 14, twice as many years.

Therefore, veterinarians recommend bringing big dogs to have geriatric checkups at 6 years old, a medium sized dog at 9, and small dogs at 11.

Theories about the aging of dogs

There are three possible hypotheses that have been handled in terms of aging of big dogs:

  • They age faster.
  • They get older earlier.
  • Their basic mortality rate is higher than that of the small dogs.

Recent research confirms the first hypothesis: big dogs age fasterWell, they do it at an accelerated pace. But what is the determining factor for it?

Dogs and the hormone IGF-1

In the body of mammals there is a hormone called IGF-1 or growth factor 1. It has been proven that high levels of this compound, in different animals (including humans), increase the risks of dying from diseases that are related to aging: cancer and cardiovascular problems.

Experiments with dogs indicate that small dogs have much lower levels of the hormone IGF-1 than large dogs. This could be the explanation by which giants age faster and die at a young age.

In any case, it is because of the high levels of stress that large dogs are subjected to or because of the low level of growth factor in the blood of the small ones, the truth is that the former die younger and it is an aspect that should be taken into account by those who decide to have one of these animals as a pet.

They have not yet discovered what exactly happens in genes

This is because of inbreeding, the human manipulation of creating "purebred" dogs to select their appearance without thinking about their health. For example, boxers are large dogs and their life expectancy is long, but the greater likelihood of serious illness can accelerate their aging. However, races of a similar size live only eight to nine years on average. How can a race of the same weight live more or less than the other species? Genetics, bad health? There is a more general reason that explains this fact.

A few years ago a study was published in which they tested three hypotheses. The first is that large dogs die younger due to an early onset of senescence (changes between the elements of the system over time), a higher risk of mortality. natural or a higher aging rate.

The conclusion of their study is that aging begins at about the same age in small and large breeds, only that the metabolism of large breeds is faster. All data indicate that large bodies have something to do with accelerated aging, but genetic components are not yet known.