Would it be cruel

Next time he comes to your door, whip it out and spray him back. That'll learn em

Are you sure a cat is the offender? Because, from what I know, a cat always hides her deposits. I would rather suspect a dog from the neighborhood, maybe a stray or something. If it is so, you can put some vinegar on your door mat. Dogs don't like the vinegar smell and they won't do their duties in a place that smells like vinegar.

At Jim's old house, one day, I noticed this AWFUL aroma while I was in the kitchen. I took the dog out to do his business and I was smacked right in the face by the odor, full force! Seemed that a tom cat (or an entire army!) decided to spray the house, right under the kitchen windows! Oh, it was worse than anything-and it was hot too! Baked cat urine has got to be the nastiest smell in the world!!!

I don't know... mark your doorstep yourself?

Hello my friend p1kef1sh Ji, Well, I suggest anti-dose , tame on Pet-Dog in your surroundings. May God bless You and have a great time

As long as it isn't a skunk go for it. Apparently they have marked your house as theirs, or someone is playing a nasty joke on you.

splat the owner

Sounds like you need a nice scratchy door mat which is awfully uncomfortable for tender feline paws and bottoms. Was it raining?

First of all, does it have an owner or is it a stray ? If it does have an owner I suggest talking to him or something and if it's stray, and you don't have a dog, you could press somme pepper on your lawn to... make her stay away ?