Planning to adopt a cat, but you already have a comfortable cat at home. It’s important to take care of yourself to ensure harmonious cohabitation between your companions. Here are 4 steps to succeed.
IMPORTANT: You should never present two cats in your arms face to face. Firstly, it could create a confrontation situation, and secondly, you could end up with a scratch in the face.
1. Upon arriving home with your new cat, place it in a single room with its necessities (food, water, litter box, comforter, etc.). Hide several small treats all over the room to encourage him to discover his space and get used to your home/accommodation. It can take a few days, you have to respect your cat’s rhythm.
Go see him often, ideally at the same time to introduce yourself and also play with him. If he prefers to stay hidden, don’t force him. Ignore him and give him time to come to you. You can stay in the room by doing a silent activity for yourself (reading, drinking coffee, writing, etc.). When he comes out of his hiding place to come to you, reward him with a treat!
TIP: A cat that feels comfortable will have its tail and head up high!
During this period, there should be no contact bewteen the cats. When you have to open the door to go play or feed the cat, make sure that it does not slip between your legs. Sudden contact with the other cat can lead to sharp altercations!
2. Quietly and routinely, exchange the cats of living environment. Let the new cat explore the house by isolating the resident cat in the room where the new cat was. Take the time to scatter treats (those he prefers) around the room; the goal being to make a positive association with the smell of the new cat. Put the new cat back in the room and let the resident cat return to its living environment.
Repeat the exercise to allow an exchange of feline scents. Do it routinely so that the cat is never suprised by the change of room. For example: in the morning after your coffee or in the evening upon returning from work.
If the cats feel under the door, let them do it. There may be grumbling: don’t intervene. If the cats have the possibility to slide their paws under the door, let them act.

To proceed the next step, the new cat and resident cat must be calm. A minimum of 3 to 7 days must have elapsed. Avoid going too fast, respect the rhythm of the cats.
3. Take advantage of a meal to feed each cat in their living environment, but in such a way that they perceive the presence of the other. Here’s how to go about it;
• Get the best possible treat (canned food, tuna, chicken, commercial treat…); each cat must have what he prefers above all.
– Do not put the cats to fasting, but make sure that they are hungry (so you can reduce the daily portion).
• Put this feast a certain distance from each side of the door (closed) and let the cats each on their own. You may have to repeat this stratagem a few times. The experience of the meal must always end in a positive way.
– If cats growl or stop eating, move one of the bowls back so they can finish their plate calmly and positively.
• As the days go by, move the bowls a few centimeters until they are stuck to the door (always closed).
– If the cats growl, back away from the bowls and resume the process.
– If the cats eat without scolding and the feast ends positively, at the next meal you can put the bowls a good distance from each side of the door and open the door a few centimeters (cats must not be able to sneak). The cats will then have to see each other without touching each other and continue eating. At the end of this meal, close the door. The tasting must be positive from start to end.
• Repeat the exercise as often as possible, at least twice a day (make sure to reduce the food portion of the cats so that they are hungry during the session), leaving the door open for longer and longer and gradually bringing the bowls closer together.
• If one of the cats refuses to eat, move the bowls away until both cats are comfortable enough to eat. To move onto the next step, cats must eat normally when the door is ajar, that is to say without scolding, spitting or kicking. It can take anywhere from a day to two weeks.

4. Open the door completely during one of the meals and let the cats interact with each other.
• This meal must be delicious to motivate the cat to eat rather than worry about the other.
– Once again, you can reduce the cat’s daily portion of food to ensure that it is hungry during exercise.
• It may be that a small altercation occurs (rumbles, kicks). It is important to not intervene. It is a negotiation that allows cats to establish their rules. If you intervene, you postpone things and the argument will last and take on intensity.
• If the situation escalates to the point of forcing you to intervene (one cat throwing itself on the other and they bite and scratch each other), throw a soft object (like a cushion) in the direction of the cats. Never separate cats using your hands or feet: you could be injured. Cat bite may require a hospital visit and antibiotics…
– Isolate the cats and contact Éduchateur.
5. In the following weeks, if everything went well, often play with your cats together. The game allows cats to know each other and associate the presence of the other with something positive.
Reference: http://educhateur.com – Méthode infaillible pour accueillir un nouveau chat, sans conflit