Cats are social animals but they are very particular about their social partners. Sometimes when you bring a new cat into a home, you upset the resident cat or the social structure of an existing cat group. This is not unusual but it can lead to some serious behavior problems.

One issue that may come up is fighting. Aggression between cats is often subtle but sometimes you can have all-out fights. Often one cat is the aggressor and the other the aggresse, while other times they are equally matched in their fighting.

When one cat is the aggressor we often see the aggresse understandably develop a fear of the other cat.

Behavior modification in this situation involves environmental management and positive counterconditioning.

Environmental management:

1. Separate the cats when you can not supervise them

2. Environment of plenty - make sure there are multiple feeding stations, litter boxes, resting spots and toys

Natural calming remedies:

1. Feliway Pheromone Therapy

2. Composure

3. Rescue Remedy 

Behavioral Management

Sometimes its necessary to desensitize the aggressive cat to wear a body harness so that he/she can be humanely controlled during the below counterconditioning sessions.

Positive Counterconditioning

This involves pairing something that both cats like (tuna juice, clam juice or wet food) with each other’s presence.

Counterconditioning Session:

With the aggressive cat on his/her harness bring both cats into a room (at first as far apart as possible) and give each a dish of something yummy. Separate them when they are done.

Do this everyday - roughly the same time because cats are habitual routine loving animals.

This will teach the aggressor to focus on the food instead of the other cat and teach the aggresse that she/he can be in the same room with the other cat without getting attacked.



Repeat this daily - moving the dishes slightly closer as you progress through the program. Eventually they should be able to eat side by side.

Additional Recommendations

1. Play sessions with you at least once each day.

2. Enrichment to increase the cat’s mental and physical stimulation (see list).

3. Clicker training