I read this on catster:
Jail Time
If your cats won't stop fighting even after trying everything above, it's time for incarceration. It's not as bad as it sounds. You want to force proximity upon the two cats without endangering either of them.
Get a large dog crate - do not use a cat carrier. Place it in a spare room, and put one cat (with a litter box and bed) in the crate, and the other cat outside the crate. Leave them alone in the room together. Do this every day for at least a week, alternating which cat gets crated.
When things appear to be less volatile between them, let them out together in the room (but don't leave them alone together). Play with them, give them treats, and praise good behavior. If one starts a fight, put him in the crate. Continue until they can be together in the room without fighting.
At that point, you can reintroduce them to the rest of the house. When one starts a fight, he goes back in the crate. Again, praise good behavior and reward with treats. Within a month, the two cats should be able to coexist fairly peacefully.
I'm going to try it with Tigger and Roxy. Roxy is still after almost a year with us, living in the spare bedroom. She and Tigger are determined to kill each other. I'm sad to say I dont understand what goes on between them. Both have been snipped, years ago, and yet Tigger tries to mate with her (I'd probably want to kill him too). Which always ends in a fight that leaves poor Roxy trembling and terrified. And Tiggy does not try to do this with any of the other girls. Dont get it :(
So here's to hoping. Will drag out the large crate this weekend and set them up. I'll keep you guys posted on what happens.
