Photo by Mike & Anna
You want to get a new cat but you already have one, and you're not sure if they will get along. A similar situation, isn't it? While some cats can become friends within hours, the others can keep hissing, posturing and chasing each other for weeks. A carefully planned introduction is extremely important. The first few weeks can set the tone for the relationship for a long time, so getting it right once and for all will save a lot of trouble later on. You need to move on slowly during the introduction process; this will increase your chances of success. Never throw your pets together in a sink-or-swim situation hoping they'll work it out themselves.

Step One

First of all, the new cat (N-cat) should be isolated in a "safe room". This room should have food, water, litter box (not near the food), scratching post, toys, and bed or other comfortable place to sleep. As soon as you bring N-cat home, take it to the "safe room" immediately. Don't stop to talk with the existing cat (E-cat). When you're in the isolated room, let N-cat out. Then take the carrier and leave the room. Put the carrier on the floor and let E-cat explore it. Some cats will exhibit great excitement while the others will hiss, growl or even attack the thing. Be ready to any reactions and behave as if nothing special has happened. Don't take the carrier away until E-cat loses interest in it. Spend at least an hour with E-cat before going back to N-cat.
Visit N-cat 3-4 times a day. Whenever you do it, be quiet and talk in a soft voice. E-cat can start hissing and growling at you because your smell will change. That's all right. Juts keep doing your routines. Make sure you still spend quality time with E-cat to help it realize its special status hasn't changed. Meanwhile, note how much time E-cat spends around the "safe room". Expect a great deal of "hissy-spitty" behaviour through the closed door from both the cats. To help the cats get used to each other's smell, rub a towel on one and let the other smell it, or swap the beds or blankets the cats use. They will eventually accept the scent as a normal part of the house. This part is, actually, more important for E-cat because N-cat will be surrounded with a lot of new smells in any case.
Do not proceed to step two until all hostile responses have ceased.

Step Two

Let the cats sniff each other through a baby-gate or a barely-opened door. Make sure neither cat can get over the 6' gate set-up, and neither can fit its head through the opening. Secure the door so that it doesn't open or slam suddenly. When you are not at home or unable to supervise, keep the door closed. Do not proceed to the next step until both the cats seem calm when they see each other. Hissing, growling and other hostile reactions should be at minimum. Take this step slowly, depending on how quickly they get along. If they do seem to tolerate each other, praise both of them profusely.
Photo by Lawrence Wright

Step Three

It's time to open the door! Let the cats mingle under your supervision but don't interfere. If they sit and stare at each other, try to distract them by dangling toys in front each at the same time. This may encourage them to play together. They may sniff each other, hiss, and then walk away. This may go on for a few days or so, and then you'll probably find them both sleeping on your bed. If you see hostile reactions, be alert as a physical battle may break out. Distract the cats before it happens (for example, throw a pillow beside them). If you've not managed to do it in time, do not attempt to stop the fight by picking one of the cats up: you're bound to get hurt. Instead, clap your hands and shout, bang a pot with a spoon, or throw water. Do something to startle them. Don't be scared by a tangled mass of fighting cats. It always sounds and looks much worse than it actually is. If non-physical methods don't stop the fight, drop a large thick blanket or bath towel over the fighters. Scope up one of them and take him or her to the "safe room". If everything has been severe like this, you may need to return half a step back.

Step two and a half

This step is necessary in tough situations. N-cat will have to leave its isolation and be set up in a cattery cage in E-cat's territory. The cats will be able to communicate but they will not have a chance to physically attack each other. Both should be fed side-by-side. If one or both are too stressed to eat, place the bowls in the opposite sides of the room. Every day move them slightly closer to each other. After 7 to 14 days, you can attempt to proceed to step three again.

Important factors

- In an ideal situation, N-cat should be younger and smaller and E-cat. Also, N-cat should be the opposite sex (or both the cats should be female), sexually immature or neutered.
- N-cat personality should complement that of E-cat. If you make a rational rather than an emotional decision and look into every candidate closely to spot its temperament, chances are it will be very rewarding.
- If you are thinking of getting a kitten to keep an older cat company, why not consider two kittens? They will keep each other company while the older cat learns to love them.
- If you already have two or more cats, use the "alpha cat" for preliminary introductions. Once the alpha cat accepts the newcomer, the other E-cats will quickly follow this line.
- Make sure you give the cats lots of snuggle time and attention so that they associate pleasure with presence of each other.
- A cat from a shelter or a rescued stray must be physically isolated from your E-cat for 10 days to 2 weeks. This is to ensure N-cat is incubating no contagious disease.
- If the only place where you can isolate N-cat is the bathroom and E-cat's litter box is located there, move the box to a new quiet place or create one with a privacy screen. If possible, do this at least two weeks prior to bringing N-cat home. Planning like this will minimize the chaos for E-cat.
- Each cat should be provided with its own food/water bowls and litter box.

The introduction process can take from two hours to six months. Don't get upset if your kitties don't want to live peacefully at once. They still have chances to become best buddies. If this doesn't happen, they will eventually learn how to respect each other and co-exist without fighting. Be patient. Slow and steady wins the race.