It is so difficult to be able to predict whether a cat will accept another into its household. Cats, as a species, have become more socially flexible, to an extent, during the process of domestication, but individuals still vary hugely in how accepting they are of other cats. Furthermore, their ability to change their sociability is limited once they reach adulthood.
Sociability refers to how comfortable a cat feels around both people and other animals, including cats. This shouldn’t be confused with boldness which refers to general confidence the cat feels towards all aspects of its environment, physical and social. Thus, a cat can be confident but will not necessarily accept a new cat because it is not that sociable to cats. Likewise, a cat can he highly social to people but not enjoy the company of other cats.
Scientists have identified some of the factors that influence how sociable a cat will be to other cats, but there are likely to be many more factors that still need explored.
Taking these factors into consideration, there are a number of areas that should be given careful thought before making the final decision as to whether to get another cat or not. These factors are all likely to interact rather than act in isolation, and therefore the more that are answered in favour of another cat, the greater the chances of a new cat being accepted.
Information about the current cat(s)
Answer these questions separately for each cat in your household and the potential new cat.
- Is the cat male or female? In unowned, free-ranging cats, groups of cats tend to comprise of related females and their offspring. However, to date, the evidence is inconclusive as to whether the gender of the cat has an influence over its ability to get along with other cats when the cats are neutered.
- Is the cat related to the other cats in the household or the new cat(s)? Studies on both unowned, free-ranging cats and owned pet cats show that cats that are related tend to show more friendly behaviours to one another than those that are not. When getting cats at different times in your life, it may be very difficult to get two that are related. Thus, if you are considering obtaining two new cats at the same time, consider siblings.
- Is the current cat neutered? Unless your cat is used for breeding, all cats should be neutered to prevent litters of unwanted kittens. Furthermore, in general, neutered cats are much more likely to get along with each other because there are no circulating sex hormones which can greatly influence behaviour. For example, in males, such hormones can cause competition between cats and increase territory defence.
- How is the health (physical and psychological) of the cat? It is generally not a good time to get another cat if your current cat is unwell. Cats that are suffering from injury, disease or stress- related problems are likely to be in a period of self-protection and are more likely to find an additional cat distressing rather than enriching.
- How old is the cat? Generally, the younger the cat, the more likely it may be to accept another cat into its household. However, introducing a kitten or adolescent to an elderly cat could be problematic if the young cat directs too much play towards the older cat, whose desire to play will be less. In such situations, two kittens who can play with one another may be a better option than a single kitten. However, the household must have the time and resources to cope with two additional kittens rather than just one.
- How would you describe the cat’s temperament? Temperament (personality) in cats has been well studied and just like people, cats differ. Some are confident while others are timid. While two timid cats may actively avoid one another or seek confidence from one another, two bold cats may clash by competing for resources. There is no set rule for which types of temperaments are most likely to get along but it is still important to take some time to think about the temperament of your current cat(s) and the new potential cat(s), particularly in terms of how they respond to new things and to change, and how sociable they are.
- What do I know about the parents and the early experiences (first 12 weeks of life) of the cat? The temperament of the kitten is shaped by both its genetics and the environment. Kittens born to parents that are sociable and friendly to other cats are more likely to be sociable and friendly to other cats as well. However, the environment also plays a big role. The period where cats are most receptive to learning about the social environment (including other cats) is the socialisation period which occurs between approximately 2 and 8 weeks of age. Kittens who have friendly encounters with other cats during this time are more likely to perceive other cats positively throughout their life. Thus, a cat that was well-socialised to other cats during this sensitive period is more likely to be accepting of other cats later in life. The chances of such acceptance are likely to be increased if the cat continues to have frequent, positive interactions with other cats throughout kittenhood, adolescence and into adulthood.
- What are the cat’s previous experiences with cats as an adult? It is true that a cat can learn to fear cats from just one negative experience. Negative experiences have very powerful effects on learning and memory. Thus, it is important to know if any of the cats have previously had any negative altercations with other cats and how this may have changed how the cat now behaves around other cats.
- What are my current cat’s current experiences with cats? If the cat currently lives with other cats, how are their relationships? If the cat has outdoor access, how does it behave towards other cats outdoors? If the cat behaves in any way anxious, fearful or aggressive, the addition of another cat(s) may exacerbate these negative emotions and behaviours.