It's a dog's life, but how long it lasts depends on a number of factors, including size and breed.
The median lifespan of dogs is thought to be 10-13 years, but the figure varies significantly depending on the breed and a number of other factors. The oldest dog who ever lived, an Australian cattle dog called Bluey, survived to an age of 29.5.
There is a surprising amount of research into the lifespan of Very Good Boys. The Dog Aging Project is an ongoing canine health study in the United States that aims to understand how genes, lifestyle, and environment influence ageing in man's best friend.
Its research suggests the median survival time is actually a little over 15 years. It found little difference between males and females but small breeds typically live longer than large ones and mixed breeds a little longer than purebreds.
One exception is the French mastiff, a relatively small dog. It is particularly susceptible to breathing and heart problems, usually attributed to the same selective breeding that led to its large, wrinkly heads. Its average lifespan is between 5-6 years, thought to be the shortest of any breed.
Read more about dogs:
Research like the Dog Aging Project is primarily conducted to increase the healthspan of our canine friends, the number of years they spend free of disease. But there's also something in it for humans. Dogs are thought to be a good model for human ageing because they suffer some of the same ailments that we do in later years, such as obesity, diabetes and arthritis.
It's hoped that a better understanding of how dogs age will eventually help humans to live longer, more healthful lives. That's got to be worth a treat.
It's a common misconception that one dog year is equivalent to seven human years, but scientists say it's not as simple as that. Dogs don't age at the same rate as we do. In the first year of their lives, dogs mature by a comparable amount as humans do in their first 15 years.
Researchers at the University of California, San Diego, have even suggested a (frankly complicated) equation for more accurately converting your dog's age into human years. You have to multiply the natural logarithm of a dog’s age in human years by 16 and then add 31.
Say your dog is 10 years old. The natural log of 10 is roughly 2.3. Multiply that by 16 and you get roughly 37. Add 31, and your pooch is therefore 68 in human years and eligible for a bus pass.
Read more about animal lifespans: