Now it is up to you. Begin by putting the aggressor in a less-desirable room behind a locked door with food, water, and a litter box. The victim cat, on the other hand, should be allowed to roam freely and have access to the more favorable areas. If there are more than two cats, group them by personality, but keep the "bullies" alone.
The aggressors should only be allowed out when they can be supervised. At the first sign of aggression, it needs to return to the less-desirable room. You may want to try leashes and harnesses to gain control of the animals. In addition, put a bell on the aggressor so the other cats always know where it is. Use rewards to condition cats to each other, such as treats, massage, and grooming. Do not use physical punishment...ever. It will only make things worse.
In most cases, behavior-modification methods work, however, it may some time to see a difference in the cat and there may be relapses. Establishing dominance over your pets is important. Your cats may never form close bonds, but they should be able to share a living space.
a) The term for the plumage on the neck of some male birds b) The term for the hairs on the backs of certain types of animals
An animal’s tendency to overpower another, in character or in activity