Cat - Establishing a Multi-Cat Household (Introducing a New Cat)

How should I choose appropriate housemates?

Cats are sociable creatures but they do not need to live in groups, like people, dogs and horses do.  This means that the selection of potential housemates is very important in order to maximise the chance that they will appreciate each other's company and live happily together.  In a natural setting feline groups are made up of genetically related individuals and the most successful multi-cat households are often based on acquiring siblings at the same time.  Groups of cats that have been reared together from an early age, without being genetically related, can also form lasting and successful social groups and therefore acquiring two kittens at the same time, and maybe even from the same breeder but from different litters, can also work well.

How should I introduce a new cat?

If you already have a resident cat and are planning to expand your feline household then the introduction of a newcomer requires some very serious thought.  One of the considerations is the age of your resident cat as well as the newcomer.  Cats do not reach social maturity until between 2-3 years of age and their social tolerance is therefore greater before that age than it is after it.  This means that the introduction process is often easier if the resident is less than 2 years of age and the newcomer is also of a similar or a younger age.  Once the resident cat is socially mature its tolerance of integration with an unrelated individual is likely to decrease but it does need to be remembered that the high rate of pre-pubertal neutering in domestic cats makes a difference to their social tolerance, and this is why so many multi-cat groups of unrelated individuals do survive relatively successfully.  If the resident is elderly it is not only potential social compatibility that needs to be considered but also differing requirements for playful interaction.  Young cats have a far higher desire for social play and an elderly cat may find the playful attention of a young housemate far from appealing.

What territorial space does each cat require?

There is no magical number for the ideal feline household and the decision as to how many cats to own has to be based on the availability of suitable territory space.  Cats divide their territory into three zones.  The core territory is the inner sanctuary and supplies the natural behavioural needs of eating, drinking, sleeping and playing.  Outside this area is a home range in which cats explore their environment and also position their latrines.  In urban environments the home ranges of neighbouring cats will overlap and elaborate feline time sharing behaviours will be used to ensure that there are minimal encounters with cats from other social groupings.  The hunting range expands beyond this and is invariably shared with a number of other cats.

What organisation is required?

Within a household it is the availability of core territory that is the prime consideration and before your new cat comes home you need to consider how you can provide sufficient space to enable each cat to have access to a safe zone in which to eat, drink, sleep and play.  In addition the availability of safe and secure toileting locations needs to be considered and this is particularly relevant if your cats are not going to be able to access outdoor latrines.  The practical implication is that any newcomer arriving in an already established feline household needs to be considered as a separate social group and when he arrives his requirement for the essential resources of food, water, resting places and latrines needs to be met without impinging on the space already occupied by the residents.  All the cats need to be able to access their resources whenever they need them and therefore the provision of distinctly separate feeding stations, watering holes, resting locations, play areas and latrines is an essential part of creating a harmonious feline household.  This takes space but it is worth remembering that cats live in a three dimensional world and making provision for use of three dimensional space can significantly increase the amount of available territory within the house.  Managing the available space is something that requires thought and planning but it is readily rewarded by the creation of a successful multi-cat environment.

Should I consider using pheromone support?

In order to maximise the success of integrating a new feline resident it can be helpful to use their natural method of communicating through scent in order to increase the perception that the home is safe for everyone.  Installation of a Feliway diffuser in the house, a week prior to your new cat's arrival, has been shown to help in reducing the level of emotional arousal in the cats and increasing their perception of the house as a safe and secure territory.  In the majority of cases the presence of Feliway for the first month is sufficient but if necessary refills can be used to continue the presence of the pheromone signal.

Will temporary segregation be necessary?

If a new cat is being brought into a household it can be sensible to begin by physically confining your new cat to a room or portion of the home with his own essential resources while allowing your existing cat to continue to have access to the rest of the home.  This allows both cats an opportunity to adapt to the smell and sounds of each other, without the possibility of direct contact or physical confrontation.  If your new cat is housed in a room with a glass door, it may be possible to allow the cats to see each other through a safe partition.  When your cats show no fear, anxiety, nor threat towards each other, you can progress to allowing access to communal areas but it is important to continue to ensure that their essential resources are in different locations.

What steps are required?

In the majority of cases the introduction of a newcomer is established through passive integration.  However, if aggressive behaviour does break out between your cats you may need to engage in an active programme of introduction, which is similar to the process which is necessary in households where social relationships have broken down.  See handout on Reintroduction for cats following hostile interactions.

What is a successful multi-cat household?

Although you may be hoping for a household in which all the cats cuddle up together in a picture postcard image it has to be remembered that a successful multi-cat household can take a number of different forms.  Certainly there are houses in which the residents are all part of the same social group and regularly rub and groom each other to cement their friendship. These households, which are often based on sibling groupings, enable owners to fill their photo albums with beautiful photographs and are readily deemed to be a success from a human perspective.  However, there are also households in which unrelated and socially distinct cats learn to live successfully together, and whilst the photo album may be composed of beautiful images of single cats, rather than aesthetically pleasing groups of cats, the household may still be deemed a success from a feline point of view.