Sorry to see about your loss Peter. 17 years is a very good age. We have 2 of our 6 cats at 17, one of whom I have to inject daily with insulin for diabetes. We had a hiccup with him recently & thought time was running out but recovered as we thought17 was a good age. To my surprise our vet told us they have 50 cats aged between 20 & 25 years as life expectancy is increasing for pets li,e humans due to better diets & medical advances.
However, we get so attached to our pets and no time is good to lose them. So much nicer than many humans.