Counter-conditioning and Desensitization
A systematic desensitization and counter-conditioning program can reintroduce feuding cats. Systematic desensitization gradually accustoms a cat to something he fears or is uncertain about. Counter-conditioning rewards the cat when he is in the presence of his "enemy," with something he needs or wants, such as food or attention. Over time, these techniques work together to make a formerly stressful experience pleasant and rewarding.
Time is the key word here. Desensitization can take months and will require considerable persistence and patience. Throughout the process, owners must be prepared to return to the previous stage at the first sign of hostile behavior before advancing to the next stage of exposure.
Neither cat should show anxiety
or aggression during the reintroduction process. If they do, go back to a distance (or level of exposure) at which both cats are comfortable. Look for signs of anxiety from the victim and aggression by the aggressor. Signs of anxiety may include not finishing the food, eating quickly and leaving, avoiding eye contact, hiding, or trembling. Warning signs of impending aggression include staring, tail switching, flattening of the ears, growling, hissing, and stiff body posture. Banish the aggressor to another room if this behavior is observed.
Reward the cats for ignoring each other. If the aggressive cat averts his gaze, he should be rewarded immediately. If the cat that has been attacked makes direct eye contact with the aggressor, reward that response. Do not give food treats or praise to either cat for showing fear or aggression; Reward only positive interactions between the cats. Steps to FollowStep I Completely separate the cats in two divided environments within your house. Perhaps one cat could have the upstairs (environment A) and the other could have the downstairs (environment B). A closed solid door should separate the two areas so the cats cannot see each other. Water and litter boxes should be accessible to all cats at all times. Make sure each cat is aware of the other's presence on the other side of the closed door, but confuse their tendency for territoriality by switching environments on a daily basis. In other words, the cat that was relegated to environment A should be put in environment B, and vice versa.
As an alternative strategy, based on the floor plan of your household, you may decide to isolate the aggressive cat in a specific room and allow the other cat to have free range of the house. Select two or more rooms with doors that you can close securely. Relocate the aggressive cat between the rooms on alternate days, leaving the door to the currently unused room open. The cat(s) with the run of the house will investigate the unused room and smell the scent of their feline housemate. Likewise, when the cat in custody returns to one of these rooms on the following day, he will smell his estranged companion's scent. The daily exchange of scents maintains cat-to-cat familiarity in a non-threatening environment and prevents either cat from becoming territorially protective toward a particular environment.
Now begins the process of desensitization and counter-conditioning. If you are accustomed to feeding your cats "free-choice," you will have to abandon this practice for more controlled feeding practices. One approach is that during the retraining period, all cats should be "meal fed" in the morning and at night so they will be hungry enough to want to participate in across-the-door socialization at mealtimes. The one thing the cats shouldn't be able to do is eat wherever and whenever they want.
Feed the cats simultaneously on either side of a closed door so they can hear and smell each other while they are eating. The food should be highly palatable. You may also choose to feed small bits of tuna, chicken, or other delectable treats.
Start by placing the bowls as far apart as necessary so the cats remain comfortable. After the cats have been eating comfortably for a few days, you can begin to inch the bowls closer towards the door. Once they are relaxed being on opposite sides of the door for at least one week, you can proceed to the next phase of reintroduction.
Use mealtimes as an opportunity to reward the cats for relaxed behavior. Pet and play with them when they are on opposite sides of the door (it helps if there are two people involved) to reinforce a new concept that really pleasurable events occur only when they are together. Owners engaging in this program should withhold all food and rewards except during these training sessions so the cats learn to associate each other's presence with food and play rather than anxiety.
When the cats are able to eat next to each other on opposite sides of a closed door, the door should be cracked open one to two inches and secured with a doorstop or hook and eye. Once the cats are happy getting occasional glimpses of each other through the crack, the opening should be widened to a four to six inches. A newspaper-covered screen with a four-inch wide strip torn off will provide an appropriate physical barrier to prevent actual physical contact between the cats. The opening can gradually be enlarged to afford the cats increased visual access until eventually the whole screen is free of newspaper. The cats should always have enough time to get used to each other at each stage of exposure before proceeding to the next step.
Once the cats are able to eat near each other across the screen, the next step is to reintroduce them to each other for a short while in the same room. At first they should be restrained on harnesses and supervised closely, one person for each cat, or be confined in separate cat carriers. They should be positioned at opposite sides of the same room and be kept there for up to 15 minutes, as long as they remain relaxed. During this time, they can be fed a meal and/or given treats, attention, or toys, whatever they prefer, to make the experience an enjoyable one. Each day, assuming things remain peaceful, they should be brought a little closer to each other and the time that they are together can be extended. The goal is to have them eating side-by-side and ignoring each other.
Once the cats are eating peacefully side-by-side on harnesses or in their carriers, the next step is to free the more passive cat from the harness or carrier. If all goes well, the more aggressive cat can be released during the next feeding while the more passive cat remains confined in its carrier.
If no signs of trouble are seen when each cat is freed individually, the next step is to try releasing both cats at the same time for side by side feeding. Next they can be left together for progressively increasing periods of time. One feeding station and one litter box should be available for each cat and should be located in open areas so the cats can always see each other and therefore not be surprised by each others' approach.
Once the cats can be together peacefully for extended periods of time, the owner should make sure to praise them or give them food treats whenever they are seen together. If the more timid cat begins to avoid the other one or if the aggressor starts intimidating the other cat, and attempting to control its movements or access to resources, it's time to return to an earlier phase of the reintroduction program.
The process described above is tedious and it may take several months to achieve acceptable results. However, no matter how frustrating it may be, do not rush the reintroduction process.
Be advised that the above techniques work well in some, but not all cases. Some cats will never be able to be left alone together but they may be perfectly happy living separately in the same household.