6 Ways to Help Cats Peacefully Coexist
The unfortunate truth is, unless they are littermates or they've grown up together, cats are not naturally social. Kitties introduced as adults, more often than not, just don't get along well. Here are six ideas to help you relieve the stress and create peace in your multi-cat household.
- A recent university study by Japanese researchers offers clues as to how cats, which are naturally solitary animals, manage to live relatively peacefully in groups with other cats
- The researchers discovered that cats with high levels of testosterone and the stress hormone cortisol maintained their distance from other cats; those with lower levels of both hormones were more tolerant during cat-cat interactions
- In addition, cats with more frequent contact with each other had greater similarity in gut microbiomes
- Another finding was that oxytocin (aka the “love hormone”), even when present at high levels, didn’t produce bonding behaviors described as "socially affiliative" in the cats, suggesting that oxytocin might function differently for typically solitary animals like cats
- There are many things pet owners can do to enrich the environment in a multi-cat household, which can go a long way toward reducing stress and aggressive behavior
A fascinating new study by researchers at Azabu University in Kangawa, Japan sheds light on how domesticated cats, known to be independent, solitary creatures, have evolved to live comfortably with others — often many others — of their kind.1
Most feline species are known to be both solitary and territorial, but since domestic kitties often cohabitate with many other cats, for example, in catteries, shelters, and rescues, Azabu University researchers decided to explore what strategies they use to live together peaceably. They did so by studying both the cats’ hormones and gut microbiomes — factors known to influence feline social behaviors.
Levels of Cortisol, Testosterone Influence Sociability
Lead study author Hikari Koyasu and team launched a two-week study of three different groups of five cats living communally in a shelter. The researchers used video cameras to watch the behavior of the cats, took urine samples to measure hormone levels, and collected poop to analyze the variety of microbial species present in their gut microbiomes. Some of their findings after analyzing the data:
- Cats with high levels of cortisol (the “fight-or-flight” hormone) and testosterone were more standoffish with other cats
- Cats with high testosterone were also more apt to try to escape
- Cats with low cortisol and testosterone were more tolerant during interactions with other cats
- Cats with more frequent contact with each other had greater similarity in gut microbiomes
- Links were found between the gut microbiome, cortisol levels, and social behaviors
High Levels of Oxytocin Don’t Seem to Affect Sociability
Another intriguing finding from the study was that unlike other animals who typically live in groups, high levels of oxytocin (the “love” hormone) in the cats didn’t translate to bonding behaviors described as "socially affiliative." According to the researchers, this suggests that oxytocin might function differently for typically solitary animals like cats who find themselves living in groups than for animals who naturally live in groups.
The researchers suggest that future studies for a deeper understanding of how cats cohabitate should include observing cats for several months (vs. just two weeks) and investigating the cause-and-effect relationships between hormone levels and social behaviors. According to the study authors:
"Low testosterone and cortisol concentrations in cats enabled them to share the space and live together, but the higher the oxytocin, the less affiliative behavior with others and the more lonely they are. The function of oxytocin was different from that of affinity for a group-mate. Cats may not consider other individuals living in the same space as tight relationship group-mates."2
Keeping the Peace in Multi-Cat Household
The take-home message for cat parents is that unlike dogs, cats aren't naturally social, and if they do choose to mingle with others of their species, it's usually with a close relative (e.g., a littermate) or a feline friend they've grown up with. It’s often the case that cats who were introduced as adults don’t get along all that well.
It’s important to realize that felines in the wild can easily avoid cats they don't like. But inside your house, your kitties have limited options to steer clear of each other. This can set the stage for feline friction, which often takes the form of one cat stalking, chasing and/or showing aggression toward another.
As noted earlier, cats are also quite territorial and should one of your kitties interfere with what the other considers his territory, such as his favorite napping spot, toy or human, the fur can fly. Often the problem is exacerbated because the cats live in close physical proximity to each other and share food bowls, litterboxes, bedding, cat perches, etc.
“Think of cats as moving around in a bubble,” says veterinary behaviorist Dr. John Ciribassi. “That determines the space between cats. They carry their territory with them.”3
Sadly, even cats who've been friendly for years, including siblings, can lose their relationship. Seemingly minor bumps in the road from a human's perspective can permanently damage the bond between cats. For example, a kitty who has been hospitalized returns home smelling like the veterinary clinic. In response, her feline housemate no longer views his long-time friend as part of his social group.
The Secret Sauce: Environmental Enrichment
There are several things you can do to relieve stress all around for the cats in your family:
- Offer lots of scratching surfaces — one for each cat at a minimum. There should be both vertical and horizontal surfaces, as many cats prefer one or the other. Also consider experimenting with different textured surfaces that offer a bit of variety.
- Make sure each of your cats has an individual, out-of-the-way resting spot. It could be the top of a cat tree or a crate (with the door left open), or a comfy spot on a closet shelf. It's extremely important that each of your kitties has at least one private area she can retreat to.
- Provide lots of toys that appeal to your cats' prey instincts, and make sure to include interactive toys that you can play with, with your cat. Also consider building or investing in a catio, which is an outdoor enclosure that allows kitties to get all the benefits of being outdoors, while keeping them safe from harm.
- Consider providing multiple perches for your cats at eye level or higher. Many kitties are drawn to high roosts because they feel safe from predators and can keep an eye on activities at ground level. You can provide access to high spaces in your home such as high closet shelves or plant ledges.
Alternatively, you can buy traditional cat furniture like cat trees, or you can get creative and design your own custom kitty perches. Try to provide at least a perch or two near windows so your cats can bird watch and keep an eye on neighborhood activities, unless you have a cat who's displaying redirected aggression. Redirected aggression occurs when a cat can't get at the thing that's bothering him — his target.
For example, your kitty sees another cat outside on his turf, but because he's inside, he has no way to confront the intruder. In the same moment, one of his feline housemates strolls into the room and comes over to greet him, and the frustrated cat goes after him.
Your best bet in this situation is to remove the source of your aggressive cat's frustration (e.g., cover the window or limit your cat's access to it) and take steps to ensure the situation doesn't progress to full-blown intercat aggression in which the housemate kitty becomes the full-time substitute target.
- Consider using natural products like those from Bach Flower Remedies or Holistic Solutions to help your cats manage stressful feelings and events in their lives. Also talk to your integrative veterinarian about homeopathic remedies that fit each cat's personality and symptom pattern to help reduce emotional responses.
Many cat parents also have good success using Feliway, a pheromone diffuser product, to reduce stress levels and ease tensions between cats.
- Finally, offer your kitties a fresh, nutritionally balanced and species-specific diet, and make sure they get adequate exercise. Many housecats today don't get the physical activity they need to be optimally healthy. Under-exercised, under-stimulated/bored cats can accumulate pent-up energy that takes the form of hostility toward other felines and/or humans in the household.