A couple of weeks before Christmas, the world’s oldest dog died in Japan. Pusuke was reported to be 26 years and nine months old. Twenty-six years is really an achievement, because only about 8% of dogs live past the age of 15. If you do the math and one calendar year equals seven dog years, that made Pusuke 182 years old by human standards.
Can a dog really be 182 years old?
The relationship between chronological and physiological age in dogs is not linear. Young dogs age rapidly at first and then the rate of aging slows down in middle age before increasing again in geriatric dogs. For example, a Miniature Poodle at one year of age is about 11 human years old; at seven years, it is middle aged at 42 human years, and 14 years old is 67 human years. Great Danes, who have a shorter lifespan than Miniature Poodles, at one year of age are 27 human years, at seven years are 59 human years and by 14 years are 98 human years.
Which dogs live the longest?
Longevity in dogs depends on multiple factors. Two important ones are breed and body weight. Owners of small dogs will be happy to learn that the smaller the dog, the longer they live. This inverse relationship of body weight and longevity is one of the unique features of dogs since the converse is true for other mammals. Take for instance the largest mammal in the world, the blue whale, which has a lifespan of 85 years, but the 1.8 gram Etruscan shrew has a lifespan of only three years.
Your dog’s breed will also affect her longevity. Overall, a mutt lives longer than a purebred dog with three notable exceptions. Miniature Poodles, Jack Russell Terriers and Whippets have been identified as purebred dogs with average lifespans longer than the average mutt. Breed also affects the diseases your purebred dog is prone to developing and will dictate some of the healthcare decisions you will make on behalf of your pet.
What about cats?
There is less information about how cat age relates to human age. A study of longevity in Swedish cats enrolled in an insurance program found 68% of Birman cats were still alive at 12.5 years of age. Swedish Siamese cats did not fare as well with only 42% alive at 12.5 years of age.