how dogs age

I learned recently that the idea dogs are “seniors at seven” comes from a study of border collies only, not a spectrum of how dogs age from different breeds. Researchers also often focus on beagles for these studies. One new paper, published in April 2021, suggests 6 new categories for understanding a dog’s age. Let’s take a look. ALSO — Answers ahead for these questions … are dogs living longer? What about giant dogs? What does all this mean?