How to Reduce Hissing, Fighting and Aggression Between Two Cats

Question

Our house has become the temporary home for my daughters two cats. They have been with us for about 2 1/2 months and everything seemed to going along fine. During this initial time our daughter and her partner were traveling around our region and returning back to our place every couple weeks or so.

Things have taken a bad turn to the worse this last week after our daughter and her partner left to go off traveling for the next 10 months or so. The two female cats have developed some animosity towards each other and will end up howling and hissing at each other with it quickly escalating to a "cats in a rolling ball" fight with fur flying unless we are right there to intervene and break it up.

So far the only solution seems to have been to try to isolate the two cats from each other by keeping them shut into a bathroom or smaller room. Unfortunately this has it's downsides because both of the cats are very social creatures and want to be by people all the time. Thus when they are shut behind the door they meow and cry in the most forlorn way.

I am looking for good ideas of how to get rid of the aggression between the two cats so they can go back to being their peaceful friendly selves in the same room.

Answer 1

First, you are doing the right thing by separating them. If they are a danger to each other when they are in the same room, then the responsible thing is to separate them until they can learn to be together again.

Second, you don't say what happened around the time that they started fighting. The most common reason that two cats who previously got along with each other will start fighting is Non-Recognition Aggression. This often happen after one cat returns from the vet.

Another common problem is Redirected/Displaced Aggression. This type of aggression will happen when a cat sees something threatening through a window or somewhere else that the cat cannot react to. The cat lashes out at the nearest family member (the other cat in this case) and forgets the initial trigger, just remembering being upset at the family member. This type of aggression is harder to determine because if you didn't see the initial trigger, it appears that the aggression just came out of nowhere.

For both of these types of aggression, the solution is to keep them separated for a period of 2-3 weeks (so that they forget whatever the cause of the aggression was), then gradually introduce them as if they had never met before.

Before letting them see each other, start scent swapping. Take a cat bed or blanket that each cat has been laying on and put it in the other cat's room for a day. Lock CatA in an extra room and let CatB explore the room that CatA has been living in (and vice versa). Let them interact under a closed door (they can smell and hear each other).

Finally, after another 1-2 weeks of scent swapping, start feeding them within sight of each other. First, they should be fairly far away from each other while still able to see each other. Gradually (over the course of several weeks) move the food bowls closer to each other so they come to associate the other cat with food (good stuff!).

It can take multiple months to get two cats to be friends again, but if they previously tolerated each other, you should be able to get them to that state again. Go slow and have patience.