Altering someone else's cat?

Has anyone ever thought of taking that irresponsible-neighbor's kitty to the vet (without permission) to get him or her altered?  My neighborhood has a white/flame point male kitty who roams, yowls, and sprays, and I assume he's someone's cat. I just want to trap him so badly and get him neutered as a community cat (ear-tipped). Honestly ought to just rehome him though. It's so frustrating! Is there anything (legal) I can do about this? If he's outside with no ID and freely roams the neighborhood? 

That's a tough question. If the cat appears to be a stray, I'd presume your action would be legal - shelters routinely have strays neutered after a short holding period.

I'd highly recommend that a thorough physical exam be done prior to neutering. I was on the verge of taking a neighborhood cat to be neutered because he was spraying all over our property. When I finally talked to his owners, I learned he wasn't neutered due to a severe heart defect, which has meanwhile killed him.

That's a good point. I have no way of knowing if he's an actual pet, or just a healthy stray (like my little colony), but I would do well to remember to examine all kitties I take responsibility for.

If he's a young, healthy cat, I think you should just take him to a low cost clinic and have him neutered. Is he a stray or a feral? If he's a feral then you will be doing him an enormous favor if you TNR him. What kind of condition is he in--does he look malnourished, or well-fed? Is anyone in your neighborhood feeding him?

Legally you should have no problems, even if the cat has a caregiver. Unless the cat has a collar with a phone number on it, you can always say you thought the cat was a stray when you had him neutered. At any rate, he's not being properly cared for if he's roaming around, yowling. He likely has fleas and parasites, too. There is absolutely nothing wrong with helping a cat in his situation.

I would advise against re-homing him unless you have someone who will assume full responsibility for him and allow him indoors. Ferals and strays often don't survive if they're dumped in an unfamiliar area because they don't know of any food sources, and often other ferals in that area will fight them and drive them away.

Your other option is to talk with many neighbors on your block and in your neighborhood and ask if the cat belongs to someone. Then have a discussion with them and offer to get the cat neutered. If the cat has an "owner," s/he may not have the funds or transportation to get the cat neutered and might appreciate your assistance.

I agree with talking to as many neighbors as you can.  I prefer to letter bomb my neighbors to let them know what I'm doing.  That way, they can't say I didn't warn them.  Plus, I've met some really cool people that are cat lovers.

I wanted to add that once you get the cat veterinarian treatment and have those records, if no other records exist for that cat, then legally you have proof that the cat is yours and there's nothing anyone can do if they're unhappy that you got the cat neutered.

Lots of good input. He doesn't appear to be friendly with people so if I manage to trap him, and he's got no ID, then its the responsible thing to get him neutered, ear tipped, and released. If he's clearly a senior kitty, or has health or breathing problems, I would speak to the veterinarian before anything is done. I worry that he has FIV, not because of his health, but because the last unneutered boy I rescued (and still have), had it. And if he does have FIV, that's a good reason to at least get him neutered. Probably bring him inside for good. Especialy if he's fighting with other cats. I don't want it to spread.