I have 4 cats and one of them is evil. We have had her for about 8/9 years and she's always been horrible (she showed up as a stray kitten and appealed to our good nature - no one claimed her from posters and no chip so we agreed to keep her - then she turned nasty!)
it used to be quite funny, things like youd walk past her and she would hiss at you when you hadn't even done anything. But now my other 3 cats are living in hell, they are all going bald because they are over grooming due to stress. They wee and poo everywhere because they are too scared to try and go out/find the little tray. They won't finish their food even when we bring it to them so they don't have to pass her. One of them won't even come downstairs because every time they do they get attacked!
I can't put her in a shelter because I can't see anyone wanting her, so what the hell can I do!! I could put up with it when it was just me but seeing the nervous wrecks the other cats have become is really upsetting! My grandma lives round the corner and she used to love letting her in and would let her stay over... She was really pleasant to her (wondering whether she hates other cats as my grandma doesn't have any) but then she bit my grandmas arm when she was trying to unlock the door and hasn't been allowed back since... So close!
Any advice on getting her to calm down? We've tried vet after vet, calming plug ins, water fountains (cats keep getting urinary infections because they won't drink their water) and all sorts and nothing is working!!
You can still take her to a shelter regardless of her behaviour. Shelters are faced with troubled animals all the time. Give them a ring and explain the situation, I'm sure they will be happy to take her if they have any space for her. And believe it or not, someone might want her. Maybe she would be happy as an only cat for someone else?
It sounds as if she doesn't like the others - and, I'm afraid, there is the occasional cat who just has a mean and troubled spirit. (Maybe she had a difficult upbringing or history when she was a stray as well.)
I'll try most things in difficult situations, but sometimes there's nowhere to go. I'd split them up.