Help! New cat is aggressive

I rescued a 2 year old cat named Mia that was left at a foreclosed home. With humans she is a total sweetie. She loves everyone she comes into contact with. However, I already have two other cats and she is constantly charging at them until they hide under the bed. Everytime she sees my other cats outside of the bed she charges at them aggresively until they go back under the bed. The only time that she is okay with them outside of the bed is at mealtimes. I did the slow introduction process. I coated them in similar smells. I don't know if there is anything else I can do to stop her from keeping my other cats in hiding. She has been in my house for two months. I know introductions take time and I wasn't expecting them all to be best friends, but I'm worried about creating a life of misery for my other cats. I literally have to find ways to distract Mia upstairs to give my other two time at the litter box and time to walk around. I never intended to get a third cat, but I didn't want to take her to a shelter and now I have really bonded with her. I truly want to keep Mia, so I'm hoping I can correct this behavior. However, if this never stops I will have to find her a new home somewhere else because I feel like my first responsibility should be to the well-being of my first two cats. The thought of this breaks my heart since I would hate for Mia to feel abandoned twice in one year.


Any suggestions? Would giving her a little squirt with a water bottle when she charges at them make the situation worse, or would that help? It helped me to train my male cat to stop jumping on the dining room table during meal times. It's just in some places you read that you need to just let the cats work it out on their own and human interference could make it worse. I have gone through the process of cat introductions before on two previous occasions. In the past I would at least see some progress at this point in time. You know maybe a little less chasing or hissing. Currently I don't see any progress at all. She is still completely in control of the entire house and my other two are terrified of her.

You didn't describe how you went about your slow introductions. Have you seen this thread on the topic? It sounds like you have to start over as if she just came into your house. Not all cats acclimate as fast as others, and this may just need to take more time.

http://www.thecatsite.com/forums/showthread.php?t=67321

I for one am opposed to using a spray bottle to deter a cat, particularly if it is for aggressive behavior. If she relates being sprayed to the other cats, she may become even more aggressive with them.

Thanks for the advice on the water bottle. I definately won't try it if it could cause things to get worse. I guess I could see how she would associate it with the other cats.

Also, I have read the other thread and I have followed a lot of the advice. Mia was locked in a different room for a week. I let them sniff out each others rooms. I gave them brief sightings at first with treats. I rubbed them in each others blankets to coat their scents. At first the interactions went incredibly well. No one really did more than a few tiny hisses here and there. Most of the time they just looked at each other and did little sniffs and nose touches. For the first week of their brief interactions I was thinking this would be the easiest cat introduction ever because I had never had such calm interactions early on. I think it was the fourth week when suddenly Mia just started charging at Lola and Winston. It was odd since I had never seen Winston even hiss at her. Lola hisses at her when Mia corners her, but mostly she tries to go about her business. I don't know what causes Mia to attack since frequently they are on the other side of the house when she does it. I haven't tried a reintroduction. I suppose I should try that next. It's just going to be difficult since Mia hates being locked in the other room and slams against the door everytime she is in there.