Make room for the newcomer
When the new cat arrives, reserve an enclosed space for him, in which he will have a litter box and a bowl at his disposal (Litter and bowl should not be placed in close proximity to each other, as the cat does not like to eat next to the place where he defecates). It must be a quiet space, a refuge, that your other cat rarely visits and to which he will not have access. It must be confined there for a few days to a few weeks. This allows him to get used to his new home. If it’s a kitten, you can take advantage of this time to make sure it makes good use of its litter box. Also take advantage of this period to treat the newcomer against internal and external parasites, so that he does not contaminate your first cat. Moreover, if it is a kitten, it is preferable to wait a week after the first vaccination before putting it in contact with other cats. Keep in mind that the introduction of a new cat represents a risk of transmission of parasites, germs and viruses between the two cats. It is important that everyone be up to date with their vaccinations. Do not hesitate to ask your veterinarian for advice.
After this adaptation period, allow your new cat to leave his space to discover the rest of the house, which is the common territory that both cats will have to share in the future.
Do not force the meeting
It is often tempting to put the two cats in forced contact. This is the best way to turn the first encounter into a stressful and trying event for everyone. It is best to let them get used to each other gradually. One solution may be to put your first cat in contact with objects bearing the newcomer’s scent marks, even before he meets him. For example, while the new cat is still confined, leave his basket at the disposal of the other, or exchange their collars.
The first encounter rarely goes well. Ideally, it should take place in a room with many exits, so that each cat has the opportunity to escape at any time. Afterwards, a clever idea is to provide your new cat with a bell collar. This way, the second cat will be aware of his arrival, thus avoiding surprise encounters. Depending on his mood, he will be able to choose whether or not to go towards the newcomer. It is necessary to let them do so, and not to intervene by seeking to protect one or to reprimand the other. The two cats will progressively establish a communication, a relationship, according to the codes of their species and their respective temperament.
Having the choice to meet or not to meet allows both cats to be in favorable conditions to accept each other.
Setting up cohabitation
It is important to leave several bowls available, all of which are regularly stocked. At first it is preferable not to have the two cats eat side by side. Ideally, each cat should be able to go and eat without having to cross the other one. They can eat in the same room, but do not try to bring the bowls too close together. This will be done gradually. It is obvious that each cat will visit several bowls, which can be a problem if one of them follows a particular diet. This situation is not easy to manage. For example, kitten food is very energetic, and if an adult cat has access to it, it can result in a significant weight gain. The cats must then be fed in two separate rooms and avoid leaving the food at will, which complicates things.
In addition, it is always necessary to have at least one litter box per cat, and even an extra one. You should also provide new hiding places, sleeping areas and observation points, so that the new cat can find its place. This will multiply resources and reduce the risk of confrontations.
It is important not to abandon the habits you had with your first cat. Continue to spend time with it as before. It is important to maintain the habits, which are soothing for the cat. If you stop spending time with him, or if you don’t behave as usual, it will be an additional stress for him.
Now that all the conditions are in place for the cohabitation to go well, you must be patient.
What to do in case of a fight?
In most cases, cats go through a phase where one of the two chicks, growls, does a round back, and tries to impress the other. However, they usually stick to threats and rarely go so far as to actually fight and bite each other. If this should happen, don’t try to interfere. There is a high risk of injury. Fights between cats are certainly impressive, but most often short and not serious. Just allow each cat to run away, leaving the doors open. Ideally, don’t intervene and let them do it. If you really fear that they might hurt themselves, intervene from a distance, for example by spraying them with a water spray or clapping your hands. Likewise, don’t try to comfort your cats after a fight by stroking them, for example. Until they are completely calmed down, you risk being bitten or scratched.
You can use pheromones, which are easily available in stores, to help you relax. Some products are sprayed in the cat’s environment, while others are applied directly to each cat to help them get along. For some cats the effectiveness is remarkable, but it is not 100% guaranteed.
What if they never get along?
This is indeed a situation that must be considered. It can sometimes take a long time for two cats to get along. Eventually, when things go well, cats can develop a true friendship or simple tolerance. They move around the house in a relaxed manner, rubbing against the same objects to register their olfactory marks, and conflicts are rare or even non-existent. Some play together and groom each other. On the other hand, some cats may never get along. In this case unfortunately, there is nothing we can do. If this becomes a real source of anxiety for one of the cats, it may be preferable to consider having it adopted by someone who can offer it a more soothing environment.
There is no way to know in advance if two cats will get along. There are no rules in this regard. Be aware that blood relations do not guarantee a good match: once adult, two cats consider themselves to be like other cats, whether they are siblings or mother and son. The only advantage is that cats from the same “family” are usually adopted together at the same time. They therefore simultaneously occupy the same territory and do not feel the presence of the other one as an invasion. On the other hand, it is not because your cat has already welcomed a fellow cat during his life that all subsequent encounters will go well.
At first, very young kittens are generally welcomed without too much aggressiveness, and mostly cause indifference. Moreover, they adapt more easily than an adult cat. They are therefore easier to introduce in a house where another cat already lives. On the other hand, trying to get two whole males to live together can be a real challenge. Finally, if your two cats are of the opposite sex, consider spaying or neutering fairly quickly if you don’t want them to reproduce.