People who like to keep several cats in their house often keep a group of unrelated cats or might introduce new comers who are unrelated. I think it is fair to say that a good number of people who want to keep several cats don’t think too much about the natural dynamics of group living and the nature of feline relationships. That said the domestic cat is very adaptable and usually adjusts to living in a group of unrelated cats – in time. But there may be underlying stresses that are not apparent to the cats’ owner. Stress can develop into health considerations such as poor lower urinary tract function. An assessment of the causes of illness in a cat or cats in a group should include a check on social arrangements and stress.
Cats living naturally, such as feral cats, tend to live in groups made up of related cats. The relationships last a long time. The bond of ‘friendship’ deepens over time and an early friendship between siblings enhances the durability of the relationship.
Unrelated cats do form a part of a group but related cats tend to interact with each other more, groom each other more and share the same bowl while unrelated cats tend to eat serially (one after another) and are, at least initially, on the periphery of the group.
The natural state of affairs in feral cat colonies is to be resistant to newcomers. The acceptance of incoming cats is gradual. Why should a cat owner think that domesticated cats living in a home will behave differently? Perhaps it is because domestic cats are more tolerant and therefore do behave slightly differently but the underlying principles apply: the most harmonious cat groups are made up of related cats. This seems like common sense to me. However, I would not expect there to be perfect harmony all the time between related cats.
One major factor that results in domestic cats being more tolerant is neutering. Most domestic cats are neutered. Most feral cats aren’t unless they are the recipients of a trap-neuter-return program.
Neutering affects how cats in a group react to incoming cats. Studies of cat group behavior in respect of neutered colonies and groups of breeding cats show that there is reduction in aggression to ‘members of neighbouring groups’ in neutered cats. There is less aggression towards strangers it seems. It is probable therefore that neutered cats are better able to live in a group of unrelated cats.
Neutering is obviously not a complete solution because there are many queries on the internet from owners of several cats about how to resolve aggression from an established cat towards a freshly introduced cat. The classic answer is to give it time, perhaps 6 months or more but sometimes time does not resolve the matter. In fact on occasion the only solution is to rehome a cat. Sometimes ‘multiple social groupings are formed. This needs to be managed by the cats’caretaker with regard to facilities.
Dysfunctional multi-cat households due to social incompatibility are stressful for all the parties including human cohabitants. The environment should allow cats to find some space (see cat colony in Morocco) and hide if required. Food and drink could be provided in more than one location. If water is put down at one location in a dysfunctional cat group a cat may limit water intake with health consequences.
Also the introduction process needs to be controlled and gradual. However, when I read some of the stories of Elisa Black-Taylor and her cats it seems that she is able to create harmony fairly quickly amongst most of her cats. I am not sure what her secret is but she does have a large dog, Dreyfuss, who loves cats and who seems to have a stabilising influence.
Apparently ‘social disruption’ in a group on the introduction of a new cat is triggered by a change in the scent profile of the group. You will even see this disruption in relationships between close brothers and sisters. I can remember my cat falling into a tub of paint! Solid emulsion paint (water soluble) so it wasn’t too bad. I had to wash her thoroughly. After washing her, her brother hissed at her loudly for a considerable time until she had thoroughly groomed herself and reestablished her scent. Cats that have been to the vet will return to a group with a different scent and may disrupt things for a while.
In multi-cat households studies have concluded that the cats do not normally create a ‘dominance hierarchy‘. This puts added pressure on the human caretaker to manage the group as hierarchies are a form of group self management by mitigating agression (reducing encounters that result in fights etc.).
I would seem sensible to think carefully about setting up a multi-cat household. Ideally the cats should be related and shelters often rehome related cats as a group (a brother and sister for example).
Associated post: Requirements of Cats Kept in the Home
Reference: The Welfare of Cats