If the Aggression Is Severe or Occurs Between Cats Who Have Never Gotten Along:
- Separate your cats as described above but for a longer period of time, and reintroduce them at a much slower pace, like several days to a few weeks.
- Instead of simply opening the door to reintroduce the cats, provide daily reintroduction sessions that very gradually move the cats closer and closer together under supervision.
- During the sessions, you might find it easier to control your cats with harnesses and leashes, or by confining one or both of your cats in crates.
- During the sessions, keep both cats distracted with food or play. Start out with them far apart. Keep the sessions short. Make it easy for them to succeed.
- Separate your cats between reintroduction sessions to prevent a relapse.
- Only when your cats can peacefully eat and play within a couple feet of each other should they be left alone together unsupervised. Trust them only for short periods together at first and increase their times together gradually.
- Behavioral medication may be helpful in reducing a domineering cat’s aggression and a skittish cat’s fear, making the reintroduction go more smoothly and quickly.