This is what 17 looks like at our house.
Graidy, our white BC mix, is 17ish–we don’t know his age exactly since he came to us as a stray at about 1 yo.
He still runs around like a puppy. Nobody can believe he’s that old when they meet him.
Wink, our Cavelier is 11. Finn, our Maine Coon cat is 14. All going strong.
I think there’s longevity in the water here. (That and lots of love, high-quality food, and plenty of exercise.)
And, of course, good genes don’t hurt.