I am going to follow those links, many thanks.
Jade and I saw the cats on Thursday and they were realy pleased to see her. Since Boots died her sister, who we have called Socks as she has small white feet has been coming around. Plus we have seen the mother cat too. We are pretty sure they are not really being cared for and are semi-feral. We put out food for them both, Socks will come in and eat but not the mother cat, she is far too scared and will only eat if food is put at the end of the pathway.
Had my operation yesterday. Day surgery and I was allowed home in the afternoon. The knee feels great, no more pain. The only down side is that the surgeon said I might need a knee replacement in 5-10 years time. Deal with that when it happens.