Have you ever wondered why several cats and even dogs can live together in small a small apartment while a spacious house may have trouble with only two cats? Some cats, particularly females, simply do not want to share. Long ago, they laid down their rules to their owners, who agreed to those rules, and who gave humans the right to change them?
Still, there are some strategies that may help in the multi-cat household.
Quarantine really helps. All cats can become aware of each other through a closed door, without seeing aggression/fear signals otherwise demanding a response hard to change later. Once the medical need for quarantine ends, cats might trade-off areas so that each can sniff out the other’s territory. When they meet, the new cat should be able to retreat to the safety of the original quarantine area without becoming barricaded into it.
Don’t even try to treat all cats “equally.” Each cat must have recognition of its special areas of primacy and its own special places. One cat might have primary rights to a window perch while another curls up inside a kitty condo. One might be king of the noisy ball chase, while another is the queen of the feathered fun. Each, of course, must be taken to the side now and then for a special treat the others don’t even know about. Cats may end up eating from the same bowl, but observe the formalities and set several places for dinner. Who decides which cat gets what special treatment? The cats do. They don’t want equality. They want respect for their individuality and areas of supremacy.
And, as much of a nuisance as it may be, set up more than one litter box and keep litter very clean.
If the house rules allow sleeping on the bed, another house rule should be that any cat who starts a spat on the bed — however justified — must leave. The bed may then become a neutral place for established and new cats to observe one another and to observe that human rules remain unchanged.
Don’t be too eager to intervene as cats hiss and growl. It can be a necessary feature of cats communicating their own rules to one another. A kitten, for instance , may pounce on an older cat, who’ll hiss and then run as if to say there is no way to deal with a kitten who can’t respect its elders. That could change into a game when the older cat feels the kitten has learned enough so that it is safe to swat and chase back. The process may take weeks or even longer. Sometimes, cats who have barely tolerated each other will confront a common stress such as moving or a new pet and form a brand new alliance.
Mysteriously, cats who have always played together may have a real fight and then become enemies.
This can happen for mysterious reasons, as an early warning of illness or if something startling happens during play and sets off one cat to give real instead of mock signals of fear or hostility. The other cat picks up on the new signals and responds in kind. The new signals then start up where the mock signals of play once had been. It may help to separate these cats temporarily if both can be in places that are attractive instead of exiling a “perpetrator.” Over a period of time without direct contact, they may forget those short-circuited signals and get a new start. Major environmental changes can start the bad behavior and adjusting the environment may give them something new to occupy their minds.