The new cat introduction process is extremely important in determining the success of having a multi-cat household. First impressions can be lasting impressions when it comes to cats. Cats’ territorial nature means that the time required for the introduction process varies greatly depending on the cats involved. Before bringing a new cat into your home, it is important to recognize that this will probably take a little bit of time and effort to make everything happen smoothly. With a little patience and commitment, your new cat could wind up being good friends with, or at the very least peacefully cohabitating with your current family cat.
Introducing cats who are strangers to each other should be done in a gradual fashion. Owners should make sure to associate enjoyable things such as food, attention, or play with the other cat(s). Patience is extremely important in this process, and it is important to know that you may be required to repeat the introduction process multiple times.
Cats are naturally territorial in the wild, and will defend their home range and its associated resources, such as food, resting areas, and litter boxes from other cats. In the case of the house cat, this territorialism may manifest in your cat becoming apparently aggressive in an attempt to “defend” his place in the household, as well as his “home range”. While this can pose quite a challenge, with some time and commitment, most cats can learn to cope with the new housemate and put major aggression issues aside. A settling in period is generally recommended before introductions are made, since the initial stress of moving into your home can cause fear or aggressive behavior to begin with.
Some cat-to-cat introductions go smoothly, while others may take weeks or months before the cats co-exist with each other. The best way to do this is to go as slowly as necessary, and make every interaction a positive one. A strong long-term relationship is built on positive encounters. Once serious problems develop, it can be very challenging to remediate. Rushing an introduction can cause such serious problems. Most cats will learn to live in a multi-cat household, and some will enjoy it more than others.
Make sure to speak quietly and calmly to the cats and make no sudden moves. When the cats are tolerant of each other’s presence, give lots of positive reinforcement in the form of words, toys, and food. It is best not to scold or use harsh tones with the cats while they are in each other’s presence. This may cause them to associate unpleasantness with being near each other. Give special attention to the resident cat(s) to reassure them of your loyalty and love and help minimize jealousy. Give the new cat loving attention only during the residentcat's absence until such time as they become true friends.
Gradual introduction can help make each encounter a positive one. This can be achieved by having separate areas for each cat. Provide each cat with their own room, litter box, food, water, toys, and a safe place to hide (such as a cat carrier with a towel inside). If there is a resident cat, choose a room for your new cat that doesn’t interrupt the resident cat’s routine. Avoid direct interactions between the cats at first. Visit your other cats and let them smell the new cat on you. Give them treats to positively reinforce this experience.
Let the cats sniff each other under the closed door from their repective areas. Let them investigate and get used to each other’s presence as long as there are no signs of fear or aggression. If that is going well, start to switch bedding and other items between the two cats. This way each cat can become used to the scent of the other without meeting face to face.
Watch closely for any signs of stress. If at any point you notice hissing, or either cat is growling,continue to keep them separate for as long as it takes for them to settle and be calm. Other signs of stress are: not eating, not using the litter box appropriately, over grooming, etc.
The next step is to rotate rooms daily for at least 2-3 days. This allows the new cat explorethe rest of the house while the resident cat spends some time in the new cat's room. This will give your resident cats a chance to smell the new cat and rub their own scent on objects. The cats should be fed in each area and it is also good to play with the cats in each area at least twice daily. The practice of setting up a schedule of feeding, as well as a playtime routine, minimizes anxiety and makes the cats feel more secure.
Keep the cats in separate areas for as long as it takes to allow them the chance to become desensitized to the smells and sounds of the cats in the other area. When they all seem particularly relaxed with this process, begin to expose them to the sight of each other.
A good way to accomplish this visual introduction is to bring the new cat(s) in a carrier to meet your cats and sniff each other through the carrier wire door. Place the carrier on the floor and allow them to meet this way several times a day for about an hour. Continue these meetings for several days or until they remain calm in each other's presence.
If and when the cats are able to stay calm in each other's presence during these meetings, it is time to let the new cat out into the rest of the house for a few minutes. The length of the visits can be increased gradually each day. Open the barrier and let the cats come into the new room and explore at their own pace. Never force cats to come into a new territory, as this will make them increasingly tense and prolong the process. Let them explore each other’s territory for short periods of time, then separate the cats and repeat this process a few times each day. The cats can also be distracted with toys or treats. This may not only distract them, but also serve as a reward for being together calmly. Never punish your cat for aggressive behavior toward another cat: it only ends up making your cats more stressed and will prolong the cat-to-cat introduction. Depending on the personalities of the cats involved, this process may take a few days or a few months. If it appears that any fighting maybe be close to occurring while you are supervising, put the newcomer back in his/her room and proceed more slowly.
At the end of each positive encounter session, separate the cats. This allows them both to regain their sense of territory and confidence, which encourages another positive interaction at their next meeting. Continue this process daily, lengthening the amount of time they are together by a little bit each session. Supervising each interaction in the beginning ensures positive encounters and allows for immediate separation should the introduction not be positive. This should be done until they are tolerating each other’s presence and you are certain that they will not harm each other.