Thank you everyone who sent supportive messages and good vibes to Fishpaste and me – they seem to have worked. Our vets are very good and today we saw the nice woman vet who addressed my lovely cat as "Fishy", while gently stroking her and probing her poor old skinny body. She reckons Fishpaste is not in pain (good news) but she is now completely blind (we thought that was happening). We all agreed that there wasn't really any point checking her liver, kidneys, whether she was diabetic and so on and so on because not much can be done at her age. We all decided to try steroid injections, so one that is effective for 7–10 days was given. We have an appointment for 10 days' time. If this one is good, she can have a 21-day injection so it's less disruptive for her.
All this happened between 4 and 4.30 this afternoon. This evening, while chopping shallots, chillies and chicken for tonight's Thai curry, I watched Fishpaste moving around while Mr absent was getting the cats' supper organised. She isn't skating with her back legs and no longer has a balancing tail like a beaver. I feel very optimistic about the next few months. Of course, you cannot turn back the clock, but perhaps she has a few more comfortable weeks/months ahead of her. Bless her dear furry face.