He had a fairly new collar on last week. Now its gone but you can still see where it had been. I'm not exactly in a part of town where lost animals get taken care of very well. There are a lot of outdoor/feral cats around.

Also, our friend noted a change in behavior the other day. The cat seemed more wary of people for a day or two, as if it didn't trust people, and then today, he was fine.

Bascially, I'm afraid of putting up found signs and having the cat returned to an owner who will not care for him properly. Even if he is seperated from his owner by accident, and that is the reason he is thin, he's still intact and roaming free. Its probably wrong to do so but I'm probably going to get him neutered anyway, and that way if he is returned and the owner lets him outside, he can't contribute to overpopulation. A responsible pet owner's first responsibility is to get their animal spayed or neutered. All of my cats are.