There is no guaranteed formula in predicting how a resident cat will respond to the introduction of a new cat. When the idea is first considered one has to understand numerous factors that may play a role in the potential success or failure with the acquisition of a strange cat for an established feline household. The scenario under discussion is purely a one-on-one case and not the situation where one cat is being brought in to a house with multiple pet cats. This also applies only to adult cats.
Is the decision behind the introduction based on the anthropomorphic belief that the single pet cat is lonely and needs a friend? Is it for the benefit of allocating a new pet for another member of the family who wants their own pet?
Is it to replace a friend that has run away or died? Cats are not cloned and often pet owners suffer from the misconception that their feline companion grew up with a cat so the addition of another one will be immediately accepted and tolerated expecting matters to continue from where the previous relationship ended. There are no two cats the same – there are always status and temperament differences, critical distance variables, genetic trait influences and environmental and social experiences from kitten-hood which renders each combination of characters as unique; and must be respected as such.
In order to make every effort for a successful and positive bilateral acceptance one has to apply certain principles based on the instincts of cats in a particular environment and past experiences from an ethological, or behavioural, perspective. Often professional advice is required.
A cat that has been raised in the presence of other friendly cats may find it easier to adjust to a new housemate. Care must be taken in the preparation for their first encounter to best avoid extended periods of conflict. Smaller properties with limited space enhance the possibility of conflict. It will probably be easier for the resident cat to accept the newcomer if their introduction is postponed until after the new cat can explore the home without the scrutiny or presence of the established territorial cat. A temporary relocation of the established pet to a cattery or veterinary practice permitting the new pet to investigate the scents, sites and space of the new turf without threats or disturbance does increase the newcomer’s status to a certain degree and, simultaneously, lowers the status of the absentee. The latter, on its return, is given full access to the domain while the new cat is confined to one room for, at least, five days. Fresh food, water, igloo and litter tray must be provided. This should be in a room least frequented by the established cat. Then you have to spend quality time as often as you can with your new pet during this period of confinement and adjustment – play, feed and pet the new cat in its new room. This will allow the newcomer to feel emotionally and physically safe in, at least, one room of the house. During this interaction the opportunity of bonding can be developed.
The resident cat will not be oblivious to the presence of the stranger. You will be carrying the scent traces of the newcomer on your clothing and skin which will help your resident cat to investigate the situation. The established cat must continue to get the impression that a status quo exists, that there is no alienation of attention and that usual contact has not altered – nothing has changed. By handling both cats at various intervals you are, in fact, cross-pollinating pheromones and other odours which, eventually, becomes familiar to both felines when they eventually meet.
Eating may be a diversion from anxiety so feeding the resident cat outside the door to the room where the new cat is being confined will encourage and allow them to approach each other but still be safe on opposite sides of a closed door. They may associate each other with the positive pleasantries of food. When both cats show no signs of growling, hissing or spitting, one may proceed with the next step which is temporarily confining the resident cat, with all the same amenities, to a favourite room such as the bedroom. Now the new cat can be released from confinement to briefly explore the rest of your home several times a day. Be vigilant during the patrol of territory for comfort and guidance. These periods of exploration can be made longer and longer periods several times each day – during which time the established cat is locked away. When the new cat shows it is comfortable outside the confines of its room then one has to take the gamble of allowing both cats to roam free for the first time. Plan it to coincide with feeding time. Stay near to observe developments. Do not show apprehension, panic or concern – cats can readily detect owner anxiety which may create an aura of anxiety thus having a deleterious effect on matters. In most instances, when the preliminary precautions have been complied with the animals will become gradually accustomed to one another as long as there is no interference from, or negative influences of, overly concerned owners. At this stage, some hissing is expected when cats try to convey the messages to one another not to invade each other’s space without expecting some sort of reaction or retaliation.
When the cats are fed in close proximity to each other they will associate their company as positive around food. As time goes by they can be brought closer and closer until there is no visible concern between them.
In highly successful introductions the owners can be fortunate enough to have tolerance and acceptance within five hours but the more difficult situations can take up to five weeks. People need to be patient and not try to force them to be friends. Not all cats are equally sociable and it takes time to determine how they will share the territory. If cats have equal standing, a rank only they can see, the introduction can take much longer because more time is needed to evaluate each other on this basis. Democracy does not exist in the animal kingdom because equal rights cause ongoing fights. Cats do not have a linear hierarchy as it exists instinctively with dogs and wolves and learnt in human armies – theirs is more of an overlapping associateship that needs to be tested at almost every meeting.
A highly dominant cat and a very submissive individual will understand their status gap fairly quickly and any challenges from the lower ranking cat will only be foolhardy.
For two cats there should be three litter trays placed in far removed strategic sites where they can squat without much chance of human or animal traffic to disturb them.
If conflict persists after the gradual introduction one may have to resort to the use of pheromones which help to appease them. These natural chemicals have been synthesized with the purpose of calming cats under stressful circumstances. If this approach fails veterinary intervention will be required where both cats may be treated with psychotropic drugs. If this does not produce the desired results, where the cats simply refuse to tolerate each other, after two months then one of the cats will have to be removed and, either abandon the idea of another cat or try a different cat that may be more compatible. Additional guidance may be obtained from an animal behaviourist specializing in the feline species.
A gradual introduction, also known as successive approximation, is safer, advisable and less stressful. For two unfamiliar cats to be exposed to each other suddenly in any given territory may be such a shock, with the sudden intrusion, causing one cat to flee for its life.
In time, the majority of cats find their place in the household and social stability returns. Introducing another cat should ensure the basic principle of the newcomer being of the opposite sex. This makes life much easier all round. Cats are not gregarious nor are they nearly as sociable as most dog breeds. A cat that has been on its own for a long time will not suffer from loneliness. Often, the idea of companionship is a human emotion and mannerism and not necessarily what the cat wants. One cannot argue the imprinting, socialization and stimulation kittens derive from each other; but this is short-lived. Adult cats have completely different needs and agendas.