Aggresive new cat

Question
If my cats pee in this new rental house, I'll have to come live with you because my fiance will kill me.I thought getting them fixed would stop that.
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Followup To
Question -
HELP!!!I have one male cat who I have had for about 7 years.I have a brother and sister who are 2 years old.They are all fixed and front paw declawed.They are all inside cats and they get along wonderfully.One year ago I brought home a stray,she(Misty)stays outside during the day and sleeps in my room at night.She LOVES the outside.We just moved into a new house. I brought her first and she's been there for about six days.She is so happy!!She has never gotten along with the other cats - she attacks them - viciously.(She also kills chipmunks)I am going to bring the other 3 cats home, hopefully tonite, but when I do, Misty is going to have to stay outside or in my room instead of having the run of the new house as she has for 6 days.She is so happy I hate to not be able to have her inside roaming the house in the evenings with us.My fiance, who likes cats has really fallen in love with her even more since she's been at the new house.How can they all co-exist peacefully in the house while we are home.Misty has claws and is so aggresive with other animals I am afraid she'll hurt my other babies before she gets a chance to "know" them. PLEASE HELP!!
Answer -
What your going to have to deal with is territorial issues when all cats are moved into the new house.  It sounds like since your new cat enjoys the new house so well, you might be considering allowing her indoors?  Thats all well and good, but when you move your other cats, they're going to be throwing a fit in addition to having to adjust to a new house.  What I would do is put the new kitty separate from the others and one at a time slowly introduce the new kitty to a resident cat.  Allow them to sniff eachother, growl and hiss, and if they start fighting a little, let them-it is part of the aquaintance process, but when you see claws or its esculating, take one of them away.  Another thing you need to be aware of when introducing a new cat to your resident cats is that some of the resident cats may "act out" by peeing, pooping, or spraying (even females) to show there dissatisfaction.  This is when you need to keep a very close eye on them and start watching for them sniffing corners of rooms, next to walls or centers of rooms.  If they see them looking for a place to "be naughty" in, throw them outside and get some cat deterrant.  I have used a product called Rebound for dog and cats when I didn't want my cat with a bad leg to jump on the window sill.  I have also used Feliway when my siamese kept peeing in corners of the dining room when I first moved and it helped break him, but I also know that if he is left in the house when he really wants to go outside, he will spray just to "punish" me.  It might be helpful for you to know that males generally pee or spray on horizontal surfaces like corners of rooms and walls and females usually pee on flat surfaces, like center  of the floor.  This is a generality and doesn't happen all the time.  I am telling you this incase you have to deal with this with your other cats when you introduce your new cat to them.  Introductions take a long time and is very difficult for everyone involved, but its worth it in the end.  Good luck and let me know how it goes.
Kris

Answer
Most of the time fixing them will stop, however some cats are more apt to spray even if you get them fixed in time.  I think its a hormone thing...some cats have stronger hormones and may act upon them by spraying and some won't.  When my cats have accidents, I use this product you get over the internet called 1.2.3 Odor Free and I recommend it to anyone with cats.  Its a kit with three steps to it that breaks down the urine, neutralizes it, and then evaporates it.  Use that for any accidents and Feliway to keep them from going back and you should still be living happily with your fiance.  Even if they are well behaved kitties and never spray or do anything wrong, it's still good to have on hand because accidents do happen from time to time.