Why do dogs have such short lifespans?
We talk a lot about improving your dog’s life span by making sure he is healthy and fit through exercise and proper nutrition. Many of us do what we can to help them live longer by following these guidelines. But if dog’s are man’s best friend, and I would certainly argue that they are, why, oh why, are their lifespans so short???
The average lifespan of dogs range from 7-8 years for some large breeds like a Great Dane or Mastiff to 14-15 years for smaller breeds like Miniature Poodles or Dachshunds. Labradors like Jack & Maggie fall in the middle with an average life span of only 12.5 year.
I did some research into why their life spans are so short, but found nothing that really provided me with any insight or answers to my question. I did find some interesting information on the the “Rate of Living” theory. This theory states that the faster the metabolism of the organism, the shorter their lifespan. Animals with slower heart rates, like elephants and whales, tend to live much longer lives. It’s not really about the size of the animal, but about the number of heart beats – most animals get about 1 billion heart beats in their lifespan, so the faster the heartbeat, the quicker those heart beats are used up and then…the heart stops beating.
Humans are the only mammal that don’t fit the mold. Here’s an interesting chart from an article that appeared in Runner’s World. You can see humans are way out of whack to the 1 billion heart beats theory with almost 3X as many beats. But as the article states, humans have benefited from advances in science, sociology and medicine which has allowed us to extend our lifespan considerably and likely accounts for that discrepancy.
But, circling back to my question about dog’s short lifespan, we do have some evidence that they are beginning to benefit from those medical advances. Between the 1950s and 1960s, pet care in America had made so much progress, that the average life expectancy of cats and dogs had increased by two to three years 1. So, while I didn’t find a specific answer, it seems that their life span is normal relative to that their fellow mammals. Here’s hoping that the trend for a longer life span seen in the 50’s – 60’s continues and our beloved pets stay with us longer and longer.