First be sure to recognise your cats’ language. Fighting and playing can look sometimes very similar.
ARE YOUR CATS BEST FRIENDS
If your cats are just playing, they should be silent, with gentle biting, retracted claws, and chasing both ways.
So if you see your cats biting seriously, fighting with claws, if you hear screams, or if chasing is only one way, they are not best friends.
The usual cause of conflict is competition for resources.
Cats don’t like to share: food bowl, water bowl, litter box, scratching post. Give each cat their own food bowl, water bowl, litter box, etc. Put them in separate areas to avoid tension caused by competition (to separate, you can put bowls on different levels: one on the floor and one on a higher spot).
Another potential cause of tension is rapid introduction of a new cat. Cats need time to adjust to a new friend.
When there is tension between your cats, it will not resolve with time.
Cats do not reconcile after conflict. Instead, tension remains permanent with subtle signs such as blocking, staring and avoidance.
Using FELIWAY Friends will help reduce levels of tension in your household. Use several Diffusers if cats use different rooms.