3 Signs Your Cat Would Not Do Well With Another Cat in the House

During the pandemic, I took in two cats: Pumpkin and Bear. They were 14-year-old littermates I found online while searching for a long-haired senior to adopt. I didn’t particularly want two cats, but I didn’t want them to be separated either, so I took them both.

They were the snuggliest, gentlest, most permissive cats I’d ever met. And they weren’t just like that with me; they were sweet as could be to each other, too. They napped together, played together, and were rarely out of each other’s sight. They had the most precious routines: They would curl up together, groom each other, tumble around in their fluffy-bodied wrestling matches, and then collapse into a little pile of fur and paws. Sometimes, I felt guilty watching them, like I was intruding on a deep and private intimacy that didn’t quite belong to me. But it was too endearing to look away.

Then Bear died. I worried Pumpkin would sink into depression without another cat in the house, so I tried fostering. But Pumpkin absolutely loathed every cat I brought home. He hissed, paced, grumbled, and after a few valiant attempts, I finally stopped trying.

I was honestly surprised. Pumpkin was so gentle, so enamored of Bear, and so social whenever friends came over. I was certain he would welcome another cat — if only I could find the right one. But he never did. 

“Cats can be social with humans and be completely different with another cat,” says Jennifer Van de Kieft, feline behavior and nutrition coach at Cat Advocate. 

Laura Cassiday, certified cat behavior consultant at Pawsitive Vibes Cat Behavior and Training, adds that companionship isn’t necessary for cats, either: “Cats are flexibly social. They can live alone or in groups, meaning they “don’t necessarily need a friend to be happy.”

The truth is, some cats simply do not want to live with other pets. Even if a cat once lived peacefully with a bonded companion or in a multi-pet household, many — after experiencing life on their own — don’t want to go back. You can try introducing them to another animal, but you may find that convincing them is harder than you expected. And forcing the issue can cause unnecessary stress, frustration, and even long-term behavioral fallout.

That’s why it’s so important to “ask” your cat — through observation, not words — before heading to the adoption center to get them a sibling. You can’t interview them about their preferences, but by paying attention to how they behave on their own, you can usually make a pretty good guess.

Signs your cat would not do well with another pet

They are territorial.

“If your cat see another cat or animal — through the window, for instance — and gets all worked up, they will probably like sharing the house with another animal even less,” Van de Kieft says.

Living on the top floor of a New York City apartment, I never saw Pumpkin interact with another cat besides Bear. I wasn’t sure whether he was territorial. What I did know was that he could be jealous. When Bear and I snuggled, Pumpkin always tried to squeeze himself in. Sometimes, he went so far as to climb on top of Bear, smothering him under his much-larger body until Bear moved and Pumpkin could settle beside me. Attention is a valuable resource for cats, and Pumpkin wanted all of mine. After Bear died, he got it, and I suspect the thought of sharing it again didn’t appeal to him.

“Even cats who were previously part of a bonded pair may not want to be with another cat,” Van de Kieft explains. “Two kittens will form their own, very specific social group, and when one of them dies you can’t just recreate that. It’s just like with humans; if my brother died, I wouldn’t be able to just go out and get another one.”

If you want to try introducing a formerly bonded cat to a new companion, you first need to give them enough time to process their loss. During this period, Van de Kieft suggests offering plenty of space — don’t force interaction — but also providing enrichment, affection, and play when they seek it out.

“I think sometimes we just do it too quickly,” she says. “And it feels like a double whammy: My brother just died and now there’s a strange cat in the house. So, give it time.”

They’ve always been a loner.

“Cats who have spent years as an only pet generally do not get the opportunity to learn social skills and proper interactions with other animals,” Cassiday says. “So, it can be difficult for them to learn as an adult how to get along with another pet.”

Pumpkin, having spent his entire life with Bear, certainly knew how to interact with another cat. But I’ve had other cats who were true loners from day one. My mother’s cat, Sophie, a semi-feral ginger badass, spent days away from the house living off rodents and small birds.

When my mom gifted me a kitten, Fremont, one Christmas, Sophie was livid. She hissed, screamed, and swatted every time he approached. It took nearly a decade before she even tolerated being in the same room as him. Looking back, I worry about the constant stress and unhappiness that tension caused both of them. Although I loved Fremont, we probably should have left well enough alone and remained a single-cat household.

They are old (and tired).

“A cat who is older and set in their ways probably won’t welcome another cat into their home,” Van de Kieft says.

Pumpkin was nearly 15 when Bear died, which is quite old for a cat, but Sophie was only six when Fremont arrived. Still, she seemed deeply settled — content with her routines and lifestyle — and the idea of a new cat in her territory clearly upended her sense of stability.

“If you have an older cat who is enjoying their life, why mess that up?” Van de Kieft asks.

And if you’re thinking a kitten will breathe fresh life into your senior cat, think again. “It almost never works out like that,” she says.

“If you are planning to adopt a second cat, try to choose one that is a similar age and energy level to your first cat,” Cassiday adds. “Do not adopt a kitten if you have a senior cat; do not adopt a very playful, high-energy cat if you have a shy or nervous cat. People often think opposites attract, but that’s almost never the case.”

How can you optimize your chances of success with a second cat?

If, after all this, you still think your cat is a good candidate for a second pet, there are steps you can take to improve your odds of finding the right match. Start by being completely honest with the rescue or shelter about what you’re looking for. They may know of a cat in foster care who fits your needs perfectly, but you won’t know unless you ask.

If possible, foster the cat before committing. Some shelters also offer adoption trial periods, which can be invaluable for making sure the fit is right.

Try not to get hung up on breed. Despite what your personal experiences or random online articles might suggest, breed does not determine sociability. “It is less about breed and more about personality,” Van de Kieft says. “I’ve done introductions for all breeds, and it’s not like one is easier than another.”

Because introducing cats properly can be painstaking and time-consuming, consider consulting a cat behaviorist before making any decisions. They can evaluate your cat, recommend what kind of personality might complement them, and help guide the critically important early steps of the introduction process.

“This is the most common reason people hire me by far,” Cassiday says. “It can be very difficult and take daily work for months or even years.”

“It’s about changing your cat’s emotional response to this new animal in their home,” Van de Kieft adds. “You’re addressing fear or aggression, so be prepared for a slow process: keeping them separated for a while, letting them see each other from far away, and using high-value treats so they learn to associate the other cat with things they enjoy.”

Also, keep in mind that a cat who doesn’t want another feline companion might still coexist peacefully with a different species, like a dog. “Cats that don't do well with other cats might do okay with a dog, because the territorial issue may not be there as much,” Van de Kieft says. Matching personalities and introducing them properly still matter, so don’t hesitate to seek guidance.

Ultimately, the goal is not to fulfill an idea of what you think your household should look like. Instead, try to honor the reality of what your cat is telling you. Some cats truly thrive as only pets, and giving them that space can be the kindest and most compassionate choice you make for them. Paying attention to their cues — whether they’re territorial, historically aloof, or simply set in their senior routines — can help you avoid unnecessary stress and keep your home peaceful.

And while it can be tempting to imagine the perfect kitty friendship, sometimes the happiest cats are the ones who get to keep their world exactly the way they like it.