The main factors that can impact the life span of dogs include breed, size, and gender. Finding dogs with the longest life expectancy isn’t easy. This is because, just as with people, researchers still don’t know what causes aging and why some dogs live longer than others.
The median life expectancy of dogs is 12.8 years. But dog life expectancies vary widely by breed. The Mexican Hairless breed, Xoloitzcuintle, has a life span of 15-20 years; the Irish Wolfhound, 6- 8 years.
But there is one proven piece of advice for people looking for a dog with a long life span – think small. Nearly 40% of small breed dogs live longer than 10 years, but only 13% of giant breed dogs live that long. The average 50-pound dog will live 10-12 years. Giant breeds over 100 pounds, such as Great Danes or Deerhounds, are considered geriatric at 6-8 years.
Generally speaking, dogs weighing less than 30 pounds live the longest. The larger your dog is, the less time he will live. It’s the weight, not the height, that matters. Some dogs are short, like the English Bulldog, but can still weigh 60 or 70 pounds. They wouldn’t be considered small breed dogs.
One last note: if you’re looking for the longest-lived dogs, look for mixed breeds and females.