It definitely heralds a new stage of life when you have to consider, as you get older, whether a pet might outlive you.
My youngest cat is 5 years old; I’m 66 and in excellent health, so I’m reasonably sure I’ll outlive him. I won’t be adopting any more kittens, ever. If any new cats come into my household, they’ll be oldies that I can reasonably expect to outlive.
I have met a couple of cats over 20, and I know one that was over 30. Just saying, for your calculations (and one of those cats did need a special diet for kidney problems— apparently 1/3 of elderly cats have such issues).
I’m surprised that Hennes, the billy goat and mascot of 1. FC Köln (Cologne), holds up with the cats and dogs in life expectancy, with only 9 Hennes since 1950.
I currently, for the first time in nearly 50 years, have only a single feline overlord. He is 16, and I have raised him from kittenhood along with his brother, who died of diabetes-related kidney failure two years ago. I have been thinking of getting another cat to be a companion to him. As much as I would love to once again experience the joy of having a kitten, I realize that at 72 it is almost certain that a kitten would outlive me. I have looked into adopting from the local animal service and found that as a senior myself I can adopt a cat over 8 years old for free.
I don’t know if the shelter I usually go to (Merrimack River Feline Rescue Society) would offer a human senior discount, but they do have a sliding scale for ages: $350 for a baby/kitten; $175 for an adult (over one year old, I believe), and $50 for a senior. They also offer partial support for medically needy cats. I could have taken that for some of my recent adoptees but I’d need to take the cat to a different vet than the office I usually use, so I chose to eat the extra expense.
And then, in 2020, an adolescent tomcat showed up meowing at the door. And, in 2022, another one.
So far nobody in 2024; which is just as well, as I’m at my at-least-theoretical four. I might outlive the current youngest cat; I might not. Provisions have been made, but they might run into their own complications.
My current dog was five when I got him. His owner left him behind when he moved. So not really old, but given the dogs don’t live all that long I figure he will have maybe 2/3 of his life with me.