Why big dogs live less than small ones
If we look at the animal world, there is a rule that usually works in the vast majority of cases: the larger an animal is, the greater its life expectancy. In this way, elephants are much more long-lived than mice and whales live longer than seahorses. But as in all the rules there is an exception; dogs. For many years we have tried to find, without answer, why large dogs live less than small ones, and today, science has already found what is the cause.
In the following article we will explain the reason why larger dogs live longer than the smallest of their species, as well as the advances that have been made to prevent this from happening.
The life expectancy of dogs
Although more than 15, 000 years ago the wolf was domesticated and the dog lives with humans, until recently we did not know the reason why older dogs live less than small dogs. First of all we must clarify that it is only a statistical data, that there is a clear correlation between the size and the life expectancy of the dogs does not mean that a large dog can not be long-lived or that a small one is not going to die young.
By life expectancy we understand the years that, on average with the rest of the specimens of their species, we expect a dog to live. And the fact is that that of large dogs is ostensibly smaller than that of small breeds, in this way while a Great Dane usually lives around 7 years, poodle bends at 14 and while a chiuaua usually lives in Around 15 years old, the life expectancy of the Irish wolfhound is 7 years.
For all this it is recommended that, in large dogs, from the age of 6 start to make geriatric check-ups and extreme vigilance measures regarding their health while in small dogs there are no symptoms of aging until 9 or 10 years.
Large dogs live less for a hormonal reason
In all mammals we can find a hormone called IGF-1, also known as growth factor 1 . As its name indicates, this hormone is responsible for stimulating cell growth and multiplication, so any alteration in its values is reflected in the size of the individual: in the case of humans, gigantism and acromegaly are associated diseases to a too high production of IGF-1.
But this hormone not only grows more, but also is associated with all those diseases that are associated with age : cancer and cardiovascular diseases. In dogs, it has been shown that the levels of the hormone IGF-1 are much lower than in their larger congeners. This may be one of the factors that explains why large dogs live less: because they age much faster than small dogs and are more likely to develop tumors and other life-threatening diseases.
Large dogs and free radicals
A recent study by Josh Winward and Alex Ionescu of Colgate University in New York has discovered a key aspect in canine anatomy that explains why large specimens are more likely to die at a younger age than small dogs.
The answer must be sought in free radicals, molecules that are released during the process of obtaining energy from food, which when they lose electrons recover them by removing them from the body's cells, oxidizing them and accelerating their aging. To prevent its effects on cell membranes, the body generates other types of molecules; the antioxidants.
The fact is that in large dogs there is an inefficient development of antioxidants, especially when they are young, so that their body deteriorates more easily than in small specimens.
To test it, they analyzed the tissues of 80 deceased puppies and dogs, isolating their cells and analyzing them in the laboratory. What they discovered while analyzing how dogs produce energy is that large dogs have a metabolism much faster than small dogs, something that causes their free radical levels to rise to the point that antioxidants are unable to stop their effects.
This discovery is very important, because with what we know now it may be possible that supplements for dog food containing antioxidants are developed so that the puppies of the larger breeds can stabilize their levels of antioxidants and lengthen their life expectancy.
