On a much sadder note, I have some bad news.
Leo stopped eating last Friday, and looked exhausted, wobbley and disorientated. On Saturday he spent most of the day hidden in the garden. I stayed up until about 2am looking after him. When I woke again at about 5am he was unable to move, and his breathing was eratic. At 8am I had to take him to the Vet where he died later on that morning.
He was at least fifteen years old.
The diagnosis by the Vet was liver failure. Leo had been seen by the Vet about three weeks ago. Nothing serious was found then. He could have had a series of blood tests, but I did not want to subject him to that. He then perked up over the following weeks. I do not think anything can be done for liver failure.