Just before I left on Monday it seemed that the other cat (not Milo who hurt his leg) was acting a bit strangely - she was hunched up and drooling. I came back this evening, and the kids said H had taken her to the vet. I thought the worst so I didn't want him to have to face it alone so I drove over. I got there just before the vet called them in. The little cat couldn't barely walk. I'm glad I was there because she crept into my arms. The vet sort of felt around and said her heart was surrounded by fluid, probably due to a growth of some kind. I asked if antibiotics would help, but she said not. I decided to take her home to think about what to do, but just taking two steps back into her carrying case made her crouch down and pant like a dog. Basically she couldn't get any oxygen into her system.
Long and short of it, I let her nuzzle up against me, while the vet gave her a lethal injection. I've never had to have an animal put down. Very distressing, as many of you know.
We got the two cats three and a half years ago, aged 11 or 12. She was very undernourished and she used to pull the fur out of her belly she was so nervous. Since then she put on weight, stopped overgrooming, and she used to let us pick her up, so I think we gave her a relaxed retirement.
Although I was worrying about her brother, she was dying. Sometimes life is marked by strange coincidences. I honestly don't think there was anything I could have done. I hope I made the right decision.