HI, Navigator. Thanks to CH for the kind words. I have had both cat and dog at the same time (cat made it her purpose in life to sit above dog height and swipe him on the back of the head if he dared pass by.
I, too, am getting on, and the responsibility of dog walking is now too much. Happily, No 2 son, took Rio, a Pembroke Corgi, to live with him. Both are happy, and cat even more so, since she no longer has to defend her dinner from an ever open mouth.
Cats are independent, and although frequently aloof, are great fun to have around the house.