Cats are often adopted in pairs, with the expectation that their lives will be socially enriched as a result of having a close feline friend. Cats that get along well tend to play together, sleep together, groom one another and will often just enjoy hanging out when the other is close by.
Seeing our cats experience this type of species-compatible joy is as rewarding for us as it is for our pets.
The significance of a fulfilling inter-cat relationship is even more evident when one cat dies. Grieving cats may stop eating, become withdrawn and appear clinically depressed. In the longer term, as a result of losing their primary incentive to play and move around, some also gain weight and become physically unfit.
When the remaining cat appears to be missing its lost companion, many owners wonder: is it a good idea to get another cat? Are there ways to match cats that are content to live together under the same roof, or could there be trouble ahead?
Bruce Smith, my friend and neighbour, recently approached me with a problem. Immediately after losing his 17-year-old cat Rocket to kidney failure, his 11-year-old cat Pantera appeared bereft from losing his companion.
Pantera spent a week searching for his absent friend, waiting outdoors for him during the day and constantly calling for him to return home. After a week or so, this behaviour subsided. But, Bruce was left contemplating if Pantera would like him to get another cat. And, why not? Pantera got along well with Rocket so why wouldn't he take to a new cat just as well?
My initial, jaded response focused on everything that could possibly go wrong. This is because a significant portion of my cat caseload involves helping to build bridges between a newcomer and previously established cats that are not getting along.
Sometimes problems arise because a young rambunctious cat harasses an older cat. In other cases owners fear their assertive adult cat will attack a smaller, more vulnerable kitten. At its most extreme, these situations can result in the cats needing to be separated, medicated and treated for secondary health issues that flare up because of the resultant stress.
And, once the fur has flown between two cats living together under the same roof, getting the cats' relationship back on track can be a drawn-out, slow process.
My initial pessimism was supported by Cornell University's 2005 study of aggression between cats that were adopted from a shelter into homes with existing cats. It found that within the first two months of adoption 50 per cent of owners reported fighting between the newly adopted and resident cats.
Throughout the rest of the year most cats had started to get along fine, but by the end of the year almost one in 10 pairs still had not.
The researchers looked into risk factors that could potentially cause cats to feud, but identifying predictors for aggression was extremely challenging.
They investigated variables such as the gender of the newly adopted and resident cats, their age, the total number of other cats in the household, their method of introduction and the size of their homes. But, statistically, none of these factors predicted whether or not the cats would fight.
The only risk factors that did provide some insight into the cats' long-term affability were how well the cats' first encounter had turned out, and the cats' level of outdoor access.
Cats that behaved aggressively during their initial encounter were most likely to continue fighting throughout the first year. Whereas if the new cat was typically friendly and playful, the original cat was the one most likely to hiss, scratch and hide.
And when one or more of the cats had outdoor access, there was more than a three-fold increase in the likelihood that fighting would occur. Interestingly, this latter finding conflicts with what other studies have found -- more resources and space usually results in less competition and fewer aggressive incidents, not more.
So, based on these points, my final advice to Bruce was to go ahead and get another cat. But, whether or not Pantera and his new housemate will get along is something of a lottery, probably having more to do with compatibility between the cats' personalities than demographic or household characteristics (something that was not evaluated in the described study).
I think that makes common sense -- not all people get along, so why should all cats?
Rebecca Ledger is an animal behaviour scientist in Vancouver.
-- Postmedia News Inc. 2014