Cats can't "work out" problems, because they're territorial animals. Stop fights between house cats by blowing a whistle, squirting a bit of water or by tossing a soft object, like a pillow, near them.read more
BY: -I’m glad that your cat has been neutered, as that procedure helps to curb aggression in male felines. The timing of the neutering can also be important, since males neutered before sexual maturity -- at around 6 months -- are less likely to spray urine, roam and fight. Observe your cats to see if you can pinpoint what instigates the fighting. Sometimes cats will fight over food, a favorite resting spot, toys or other items. Keep a squirt bottle full of water handy to break up the fights. This may help to discourage the bouts from occurring in the first place. You may have to call in a cat behavior specialist, but before you do that, try redirecting your male cat’s aggression. Spend time playing with him to work off his excess energy. It’s better that he pounces on a pole toy feather or a mechanical mouse than on one of your other cats.
Cats reach full skeletal development when they are this old: