I'm so glad that the peeing and pooping has stopped!! If you look on here, there are many many people with multiple cats. In our home, we have had rescues in and out for the last 6 or 7 years while Jasper has been here. Sometimes they get along and sometimes they don't, but eventually they have ALL dealt with each other when they realized that "Hissy" fits weren't going to get rid of each other!! Cats are like people, all have different personalities and some just don't ever get along. That said, even if Meg and Zorro never become friends they will eventually just agree to disagree and probably stay away from each other. You might always have some spitting and hissing when paths cross, but as long as the hardcore physical stuff stops...and it will...things will be ok.