If your dog is ten years old, its equivalent age in human years ranges from 56 (small breed) to 78 (giant breed). (oregonvma.org)
Upon reaching the «age» of 24, a cat then ages four human years for every calendar year. (mnn.com)
What this means is that small dogs age more quickly than big dogs in their first couple of human years but slower than big dogs once they hit adulthood. (bbc.com)