Deciphering Ages and Stages in Cat

Of all the myths about companion animals, one that persists (and keeps pushing me back) is the idea that cats (and dogs) age at a rate of seven years for every human year.

Honestly, this idea didn’t make sense to me. We have all seen (or at least known) cats that have lived to the age of twenty. Using the 1-equals rule of 7, a 20-year-old cat would be equivalent to a 140-year-old person, which is simply not possible. Now let’s think about reproduction. Cats and dogs can become pregnant and give birth to offspring as early as 6 months of age. Using the rule of 1 equals 7, a 6-month-old cat is equivalent to a 3-year-old human. Can people have children at this age? of course not! The 1-equals 7 rule doesn’t work for the simple reason that cats age faster when they are younger and slow down as they get older.

How do cat years compare to human years

Several years ago, the American Association of Feline Practitioners (AAFP) and the American Animal Hospital Association (AAHA) collaborated to create an age comparison chart that takes this into account. (See sidebar). According to this graph, a one-year-old cat is equivalent to a 15-year-old person, and a two-year-old cat is like a 24-year-old person. Then, you add four human years to each cat year. This is a more reasonable approach, and in my experience, it seems pretty accurate. Note: This chart does not apply to dogs. Dogs have different age formulas depending on their size (large dogs have shorter life spans than small dogs, for example). Cats are all roughly the same size, so the graph is universal for cats.