Will My Cat Get Along With Another Cat? How to Tell

Name: Will My Cat Get Along With Another Cat? How to Tell
Creator: Dr. Zubair Khalid

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-10-03

You can get a good read on whether your cat will accept a second cat by looking at three things: how your cat was socialized as a kitten, how your cat behaves around other cats now, and how much your cat depends on a stable routine. No test predicts the outcome with certainty, but the pattern of your cat's past and present behavior tells you a lot. This article is educational and is not a substitute for veterinary diagnosis or treatment.

Quick Answer

Cats socialized to other cats between 2 and 7 weeks of age are far more likely to accept a housemate later in life [1].
A cat that grew up as an only cat with little feline contact often reacts strongly to a newcomer out of fear and lack of social skills [2].
Watch for friendly signals: slow blinks, nose touches, rubbing, sleeping near another cat, and relaxed ears and tail.
Watch for stress signals: hissing, growling, hiding, spraying, blocking doorways, and guarding litter boxes or food.
Two unrelated males or two unrelated females often have a harder time sharing space than a mixed pair [2].

Why Cats React the Way They Do

Cats Are Flexible, Not Solitary

The old idea that cats are loners is not accurate. Cats have a flexible social structure. In feral conditions, cats live in groups made up mostly of queens and their litters, along with a few males [1]. Group size depends partly on how food is distributed. When food is clumped and reliable, cats tolerate each other. When it is scattered, they spread out.

That flexibility explains a lot about your cat at home. Your cat can enjoy company, but only on terms that feel safe. A new cat changes territory, scent, and routine all at once.

The Socialization Window Matters Most

The socialization period runs from about 2 weeks to 7 weeks of age [1]. During that narrow window, kittens are most open to new experiences. Exposure to other cats, other animals, people, and a range of sights, sounds, and smells during this time helps prevent fear later [1].

A kitten raised in a home with littermates and a mother cat learns bite inhibition, greeting rituals, and how to read feline body language. A kitten raised alone, or separated too early, misses those lessons. If your cat grew up as the only cat with little or no contact with other felines, your cat may react strongly to a new cat because of fear of the unknown, missing social skills, and dislike of disruption [2].

Territory and Personality

Cats are a territorial species. Some cats overlap their territories a great deal, while others prefer to keep a good distance from neighbors [2]. Two unrelated males or two unrelated females may have a particularly hard time sharing space [2].

Personality clashes also matter. Cats usually do not get to pick their housemates, and sometimes the match is simply wrong [2]. Even cats that got along well can develop tension later. If one cat reaches 1 to 3 years old and trouble starts, social maturation may be a factor [2].

How to Tell If My Cat Will Get Along With Another Cat: Signs to Look For

Signs Your Cat Is Likely to Accept a New Cat

Your cat lived with other cats before and shared space without fighting.
Your cat seeks out other cats at the window, on walks, or in a catio and stays relaxed.
Your cat rubs, head-bumps, or slow blinks at other cats.
Your cat recovers quickly from surprises and adapts to new furniture, guests, or schedule changes.
Your cat plays vigorously and seems to want more interaction than you can provide.

Signs Your Cat Would Rather Stay an Only Cat

Your cat hisses, growls, or swats at cats it sees outside.
Your cat sprays, middening (deposits feces outside the box), or scratches walls and furniture after seeing another cat [1].
Your cat hides for hours after a visitor brings a pet smell into the home.
Your cat guards food, water, or litter boxes.
Your cat is easily startled and takes a long time to settle after a change.

Reading Body Language

Body language is made up of postures, facial expressions, and the position of the ears, tail, and whiskers [3]. Cat body language is subtle and can be hard for people to interpret, but knowing the basics helps you respond to problems more effectively [3].

Relaxed signals include ears facing forward, a tail held loosely, and slow blinking. Stress signals include flattened ears, a puffed tail, a crouched stance, and a fixed stare. Aggression in pet cats can range from hissing and avoidance to full attacks [3].

Watch How Your Cat Handles Group Settings

If your cat has ever been in a group setting, think about what happened. In one study of a cat café, cat-to-cat interactions were infrequent and mostly friendly, and avoidance was the main way cats reduced conflict [4]. That is normal feline diplomacy. Cats often manage group life by staying out of each other's way, not by becoming best friends.

If your cat's style is to avoid and keep distance, a second cat can still work, as long as you provide enough space and separate resources.

Medical Causes to Rule Out First

Before you blame personality, rule out pain and illness. Dental disease, orthopedic problems, and heart murmurs are common in aging cats. In a long-term study of 209 aging cats, dental disease appeared in 84%, orthopedic abnormalities in 82%, and heart murmurs in 59% over the study period [5]. Most cats in that cohort developed at least one abnormality on veterinary examination [5].

An uncomfortable cat is a less tolerant cat. Arthritis can make a cat guard resting spots. Dental pain can make a cat irritable around food. Thyroid disease, chronic kidney disease, and sensory decline can all change how a cat responds to a newcomer.

Schedule a wellness exam before adding a cat. Ask your veterinarian to check teeth, joints, heart, and baseline bloodwork. If your cat has a sudden change in how it treats other cats, that is a medical question first. See Why Is My Cat Suddenly Aggressive Towards Other Cats? for more on sudden shifts.

When Cat Company Becomes a Problem

Cohabitation problems between cats are a real welfare concern. They can affect the cats involved and strain the bond with their owner [6]. Problem behaviors like urine marking, scratching, fear, and trouble living together are common reasons owners seek help [6].

Signs that the arrangement is failing include:

One cat hides most of the day and only comes out when the other cat is shut away.
Litter box avoidance, spraying, or marking on walls and doors [1].
Mealtime tension, weight loss in one cat, or food guarding.
Staring, blocking, and ambushing that never resolves.
Redirected aggression toward people.

Some conflict has a clear trigger. Cats can get along fine until something scary or unpleasant, like fireworks or the smell of the veterinary clinic, becomes linked to the other cat [2]. That kind of tension can often be repaired with a careful reintroduction.

What to Do Step by Step

1. Assess Before You Adopt

Answer these questions honestly. How old is your cat? How long has your cat lived alone? Has your cat ever shared a home with another cat, and how did that go? How does your cat react to cats outside? How much does your cat rely on routine?

If your cat has a history of successful cohabitation, your odds are good. If your cat has always been alone and reacts strongly to outside cats, plan for a slow process and consider whether a second cat truly fits your home.

2. Choose the Right Match

Temperament matters more than looks. A confident, playful kitten often works better with a tolerant adult than another adult with a similar strong personality. Two unrelated males or two unrelated females may struggle more than a mixed pair [2].

Age also matters. Kittens are still in or near their sensitive period, which makes them more adaptable [1]. Older cats often prefer calm company or none at all.

3. Set Up the Environment First

Cats are strongly influenced by scent. They mark with urine, feces, scratching, and rubbing cheek and body glands on the environment and on other cats [1]. Neutering may prevent or resolve urine marking, roaming, and fighting with other cats [1].

Before the new cat arrives:

Add at least one more litter box than the number of cats, in separate locations.
Set up separate feeding stations with visual barriers.
Add vertical space: cat trees, shelves, and perches. In the cat café study, elevated structures were important, especially when the space was busy, and cats preferred vertical levels or cat-only rooms during high occupancy [4].
Create two complete "territories" so each cat can eat, sleep, and eliminate without passing the other.

4. Introduce Slowly

Do not put the cats face to face on day one. Start with scent swapping, then barrier introductions, then supervised time together. Feed both cats on opposite sides of a closed door so they associate each other's smell with something good. Extend the time together only when both cats stay relaxed.

For a full walkthrough, see How To Introduce A New Cat To Your Resident Cat. If you want a shorter version, How To Introduce New Cat To Cat covers the same steps in less detail.

5. Use Enrichment and Pheromones

Interactive play, food puzzles, and climbing space reduce tension. In one study, more socialized cats were more likely to solve a food-acquisition puzzle, solve it faster, and approach the new object sooner [7]. Enrichment gives your cat an outlet that does not depend on the other cat.

Feline pheromone products are sometimes used to reduce problem behaviors in multi-cat homes [6]. They are not a cure, but they can support a behavior plan.

6. Give It Time

Expect weeks, not days. Some pairs settle in a month. Others take several months. Some never become friends but learn to coexist, which is a reasonable outcome. Friendly interactions in group settings are often infrequent, and avoidance is a normal way cats keep the peace [4].

What Not to Do

Do not punish either cat. Punishment increases fear and can make aggression worse.
Do not force interaction. In one study, forced interactions raised cortisol and lowered oxytocin, while passive interactions did the opposite [8]. Let contact happen on the cats' terms.
Do not assume a hiss means failure. Hissing is communication, not a verdict [3].
Do not skip the slow introduction because "they will work it out."
Do not add a second cat to fix a lonely cat without checking whether your cat actually wants feline company.

When to Get Professional Help

Call your veterinarian if you see:

Sudden aggression between cats that previously got along [2].
Spraying, middening, or scratching that starts after the new cat arrives [1].
One cat hiding, not eating, or losing weight.
Wounds, limping, or fur loss from fighting.
Any behavior change in a cat over 8 years old, which may point to pain or illness.

Your veterinarian can rule out medical causes and discuss behavior modification. A certified behavior professional can build a step-by-step reintroduction plan for your home. For sudden aggression, see How Do You Introduce A New Cat To Your Cats for reintroduction guidance.

Limitations and When to Contact a Veterinarian

No checklist can predict how two individual cats will feel about each other. Temperament, age, health, history, and home layout all interact. Your cat's behavior at home is the best guide you have, and even that can change with illness or stress.

Contact your veterinarian the same day if a cat is not eating, is hiding constantly, or is vocalizing in pain. Seek emergency care now for open wounds, heavy bleeding, difficulty breathing, collapse, or a cat that cannot urinate. Schedule a routine visit for gradual behavior changes, new spraying, or tension that has lasted more than a few weeks. Every individual case needs a veterinarian who can examine the cat and review the full history.

Frequently Asked Questions

Can a cat that has always been alone learn to like another cat?

Yes, some can, but the odds are lower and the process is slower. A cat raised with little feline contact may lack social skills and fear the unknown [2]. A calm, well-matched companion and a very gradual introduction give the best chance.

Is it better to get a kitten or another adult cat?

It depends on your resident cat. Kittens are still within or near their sensitive socialization period, which makes them more adaptable to new situations [1]. A confident kitten often pairs well with a tolerant adult, while a shy adult may do better with a calm, similar-aged cat.

Do two male cats or two female cats get along worse?

Two unrelated males or two unrelated females may have a particularly hard time sharing space [2]. That does not mean same-sex pairs always fail. Neutering reduces urine marking, roaming, and fighting with other cats [1].

How long does it take for two cats to get along?

It varies widely. Some pairs settle within weeks, and others take months. Friendly cat-to-cat contact is often infrequent even in stable groups, and avoidance is a normal conflict-reduction strategy [4]. Coexisting peacefully is a valid goal.

Does hissing during the first meeting mean they will never get along?

No. Hissing is a normal communication signal, and aggression in cats ranges from hissing and avoidance to outright attacks [3]. Slow the introduction, add barriers and separate resources, and let both cats set the pace.

References

Social Behavior of Cats - Behavior. Merck Veterinary Manual.
Aggression Between Cats in Your Household. ASPCA Animal Poison Control Center.
Aggression in Cats. ASPCA Animal Poison Control Center.
Cats in a Cat Café: Individual Cat Behavior and Interactions with Humans. Animals : an open access journal from MDPI, 2025.
Patterns of morbidity, multimorbidity, and mortality in aging cats: findings from seven years of the Cat Prospective Ageing and Welfare Study. Frontiers in veterinary science, 2026.
Development of a Cat Behaviour Issues Assessment Scale (CABIAS) Assessing Problem Behaviours in Cats. Animals : an open access journal from MDPI, 2023.
Effects of Socialization on Problem Solving in Domestic Cats. Animals : an open access journal from MDPI, 2024.
EXPRESS: The hormonal effects of owner-cat interactions on pet cats of different potential attachment styles. Journal of feline medicine and surgery, 2026.