But it's up to you! If it's an unnuetered male, and you know of a no kill shelter (or a kill shelter that you have a good relationship with and will call you before they do the duty and call you so you can come get him) then I say let him go to a home where-in which he will be nuetered. OR, if you do keep him and place notices around. Don't place pics. Ask for a description AFTER you ask if he's nuetered and if they say no, ask why, and if they give a lame reason, "cuz we want him to have fun", then, ask for description, and then say, sorry, doesn't match description, good luck finding your boy! (QSL's trick in making sure home cat is returning to is ok- sometimes people just can't afford it in which case you can facillitate the next step!)
If the cat was emaciated, to me kitty is unowned or at least neglected and should have a chance in a new home...