December 17, 2016

Comparative Longevity of Pet Dogs and Humans: Implications for Gerontology Research

This study’s goal was to determine the correlation between body mass and lifespan in dog breeds. Researchers studied results from well over tens of thousands of dogs in the Veterinary Medicine Database (VMDB) in order to search for these correlations. There was also a secondary goal of comparing the ages of dogs with the physical ages of humans; i.e. matching the ages of dogs going through adolescence, maturity, etc. with the respective age in humans. One interesting trend in the database was that the median age of death was very low, with most dog breeds falling below 7 years of age. The researchers believe the reason for this is that many of the dogs in the VMDB were referred to veterinary teaching hospitals by their general practitioners, and were already very sick. They ruled out euthanasia as the cause of the low median, as the median age  of dogs who died of euthanasia lied above the median age of all dogs.

The data showed that body mass was inversely proportional to lifespan, and that purebreds on average have shorter lifespans than mixed breeds. This was to be expected. The researchers did find that purebred dogs for the most part had shorter lifespans across all weight classes, implying that controlled breeding has greater negative effects on lifespan than body mass. The researchers mapped the age of these dogs against their human-age equivalents. They did not believe a linear scale would represent the developmental differences in the dogs’ lives, so their “human” ages were fit to third-degree polynomials. The purpose of this is to give a sense of the rate at which dogs age in terms of physical maturity.


Reviewed by Jason Hammerman.

Original article:

Patronek, Gary J., David J. Walters, and Lawrence T. Glickman. "Comparative Longevity of Pet Dogs and Humans: Implications for Gerontology Research." Journal of Gerontology 52A.3 (1997): B171-178. Comparative Longevity of Pet Dogs and Humans: Implications for Gerontology Research. Web. 14 Nov. 2016.