Mary Allen
Small dogs usually live longer than their larger dogs. US biologists recently wondered why this is so. Result: Dogs’ lifespan may be related to their height.
In the animal kingdom, there are many different life spans – from a few hours over decades to centuries. One of the factors affecting the lifespan of animals is their size.
Smaller animals often have a higher “work pace,” for example, breathing and heart rate increase. This is a big load on the body, it, so to speak, “wears out” faster.
However, in the case of dogs, the opposite is true: smaller dogs usually have a longer life span than large ones. For example, a Chihuahua lives on average three to five years older than a Labrador Retriever.
Small dogs have a lower metabolic rate, which is associated with a shorter lifespan than most other small mammals.
But researchers believe small dogs still live longer. The magic word: oxidative stress.
Oxidative stress can damage cells in the body and is caused, for example, by high metabolism. Large breed dog puppies quickly get larger and heavier, so their metabolism does improve from an early age. Researchers from the United States have found that this already in puppyhood causes irreparable damage to their cells.
Rapid Growth Can Reduce the Lifespan of Large Dogs
The researchers came up with this result by examining tissue samples from puppies and adult dogs, both small and large breeds. In doing so, they especially investigated the presence of free radicals and metabolism.
And they found that the cells of large dog puppies are surprisingly rich in free radicals. Apparently, the cells could not compensate for the overproduction.
In contrast, small breed puppies did not have an excess of free radicals, according to the journal Research and Knowledge.
Takeaway: Large breed dogs grow faster and therefore can age faster in general.