There have been a lot of posts about cats not getting along. We have 14, and as you can imagine, not everyone gets along with everyone else. There is Nimbus who hates being inside, but when she is in to eat, she growls and swipes at anyone within reach. Then there is Squirrel, the former feral we brought in while she was pregnant (though we didn't know it at the time). She spends more time inside than Nimbus, but still doesn't like folks getting close to her, though she lets cats get closer than Nimbus. Then we have Domino, the oldest female....she hates Nimbus, Squirrel, and the other older female Sundae.
Now Domino will actually stalk and attack the above mentioned females. It sucks when she does that and we try to stop her when it happens. Nimbus and Squirrel go out of their way to avoid confrontation, but with so many cats, someone inevitably gets too close for comfort.
If we took Domino out of the house, I think we would have no problems except for the occasional swat; we wouldn't have attacks. But Domino gets along great with the younger cats and even plays with them, and she is really a sweetie most of the time. We just accepted the fact that certain cats will not get along and love and clean each other, etc. Please don't get the idea that there is constant fighting in our house, there isn't. In fact, right now Domino and Squirrel are sleeping on the pool table within 2 feet of each other. I think that it's just that Domino is moody.
So I guess the reason for this post is that if you have a couple of cats that don't get along, especially if one is a newcomer, don't get stressed. Give it time....and even if they don't get along, they'll establish their own limits and boundaries. They will still have spats from time to time, but it's really nothing to get worried about unless someone is getting hurt.
This is Nimbus (back) and Squirrel using the same chair. They ended up sleeping there together for a couple of hours.
Things evolve. Next thing you know, they'll be cleaning each other