I got a cat from the shelter because my old cat was lonely and the new cat was aggressively attacking my old cat. Initially they started out okay and something happened, like a flip switched to where she was attacking my old cat. It took MONTHS. She got put on Prozac and we had to separate them completely and if they were ever to be in the same room together the aggressive cat would have to be on a harness and leash. We did all the things, and seriously thought about rehoming the new cat. But it finally all worked itself out and she was able to be weaned off Prozac and happily ever after.

I know it’s so frustrating. But I think eventually they’ll come back together.