Jenni, I don't know if this will help, but my Tansy who is 21yrs, is also quite skinny, (old cats lose muscle tone which makes them look skinny) and is eating well, and seems quite happy, but since the weather became so very cold, she has never attempted to go outside, and has used the cat litter tray (which has always been there, not used very often, but there for possible night-time emergency use). Now she uses the tray all the time as needed, and likes to lie in front of the fire, or on a rug in front of the dining room radiator. So perhaps it is to do with it being so cold, as she is seeking extra warmth. It did occur to me that when your cat had its distressing accident, that it could have had a chill, which could have caused it. I'm glad that he is now using the litter tray. If he continues to eat well, keeps using his tray, seems content, and is kept warm, I think a few more days to see how things go might well be the thing to do. Then if things stay like that, I would suggest a trip to the vet to get him checked out. Old cats are like old people, they do feel the cold much more, and need extra warmth and care. By the way it seems we shouldn't be talking of him as 'him' when he has a name. What is it? You have had such a lot of good advice from the lovely people on here, which I'm sure has been a help to you. Every person who has replied has shown a lot of concern for both you and your cat. Please let us know how things are progressing, and remember there's always someone on here to talk to who understands how you are feeling. Love to you and cuddles for puss. Schutz.