Cat Introduction Nightmare? Follow These 8 Steps

Introducing a second (or, if you’re like me, sixth) cat to your home can be a fun and exciting time, but it can also be a little nerve-wracking. What if your new family member doesn’t get along with your other pets?

It can be stressful if things don’t work out. Your other pets may not take to the new addition very well, and you might suddenly find yourself spending a ton of extra time you don’t have trying to herd cats. Quite literally.

If you’re struggling to introduce a new cat to your home, don’t worry. In this article, I’ll focus on how to fix a cat introduction that’s not going well. And while there are no guarantees, the steps I’ll outline here will give you the best chance of success.

What do I do if my cat introduction isn’t going well?

The first thing is to remember that it’s normal for this to happen. So don’t be too hard on yourself.

The good news is, there are several things you can do to try to improve the situation, both for you and the cats. Because living with warring felines is no picnic for anyone!

#1. Separate the cats

Go back to square one and start again. When things aren’t going well, it’s important to give everyone some breathing space to calm down, regroup and destress.

Start with keeping your new cat in a separate room, where he can feel safe to explore and settle into his new surroundings without the stress of other cats being around.

The same goes for the existing cat (or cats). Give them a break from the tension and let them have some peace and quiet for themselves.

Make sure to provide the new cat with food, water, a litter box, a scratching post, bedding, hiding places, and toys in his safe room.

Be sure to give him plenty of playtime and attention during this time as well.

#2. Learn to read your cats’ body language

Understanding your cats’ body language is essential. You’ll need to know when they have destressed so you can move on with the reintroduction process.

How do I know if my cat is feeling fear, anxiety, or stress?

Signs of fear, anxiety, or stress in cats can include:

• Flattened ears
• Tail twitching or lashing
• Hissing or growling
• Hiding or fleeing
• Scratching or biting
• Freezing/stiffened posture
• Stiffened fur (aka piloerection)
• Dilated pupils

If any of the cats are displaying any such signs of stress, they’re not yet ready to move to the next step.

Wait till you’ve got relaxed behavior and body language from everyone.

How do I know if my cat is feeling calm and relaxed?

Signs your cats have destressed and will be in a more positive emotional state to work through the reintroduction process can include:

• Relaxed muscles/soft body posture
• Purring
• Soft, slightly lowered ears
• Loose, relaxed tail
• Slow blinking
• Rubbing against objects or people
• Playing and interacting with toys or people

If you prefer a visual rendering of feline body language, here’s a great video from Battersea Dogs and Cats that showcases the essentials:

Once you’re sure all your cats are happy and relaxed, you can begin the reintroduction process.

How long should I keep my cats separated?

This depends very much on the cats. There’s really no set amount of time.

Some cats may take just a few days, while others may need a few weeks to destress.

The best thing you can do is let your cats set the timeline. It won’t work if you try to force them to adhere to some arbitrary schedule you’ve devised.

#3. Gradually reintroduce the cats

After a few days or even weeks of separation, it’s time to start reintroducing the cats once you’re sure everyone has calmed down.

This should be a slow and gradual process and you should treat it as if it’s their initial introduction. Try to forget about whatever happened before. This is kitty introductions 2.0.

It’s important to not rush any of this, as forcing the cats together before they’re ready can worsen the situation and make it harder for them to form a positive relationship in the future.

To reiterate: You’ll only start reintroducing the cats once you’re reliably seeing relaxed body language from all the cats.

Scent swapping

It’s a good idea to start by swapping their bedding or toys so the cats can become accustomed to each other’s scents before reintroducing them face-to-face.

You can also swap them around so the current cat gets to explore the new cat’s space, and the new cat gets to explore the rest of the house.

Be careful when you’re maneuvering the cats around. Try not to let them see or have access to each other.

If they settle in each other’s area, that’s fine. Let them stay for as long as they like.

If they want to go back to their separate areas, you’ll need to carefully maneuver them back again.

I hate to tell you this but sometimes a cat may spray as a way of spreading his scent and marking his territory, or overmarking where the other cat has been.

If this happens just distract him with a toy or a treat, or just call his name. Anything to interrupt the behavior. Don’t shout or punish him though as that’ll just make him feel more insecure.

Moving swiftly on…

Mealtimes

After some successful scent swapping where everyone has stayed calm and relaxed, try feeding the cats a few yards apart on either side of a closed door, so they can start associating something positive (food) with each other’s presence.

For this purpose, I’d use food that they really love, something really special like tuna fish, sardines, or chicken baby food. This is in no way advice on nutrition, but simply a way of using something your cats value highly and probably don’t have access to at all times.

You can also use some tasty treats like Dreamies, which my cats love. The idea is that they learn to associate this high-value food that they don’t normally get with the presence of the other cat.

Tuna fish you said? Dreamies? Your presence means good things happen! Maybe you’re not so bad after all!

Another option would be catnip, although some cats get a little over-aroused which defeats the purpose!

Either way, find the distance the cats can happily tolerate and remain calm, then gradually, over a period of several days, start moving their food bowls closer together.

This means moving them very small distances (a few inches) at a time and staying calm.

The goal is to keep the cats under threshold at all times. This means they should not be showing any signs of negative emotional arousal (see #2).

If they do, give them a break, then go back a step and restart from there.

Whatever you do, don’t rush this part. It may seem tedious and over-fussy, but in the long run, it’ll be well worth it.

#4. Visual contact and play

Once the cats are happily eating together on each side of the door you can start to open the door an inch or two and let them see each other.

Keep it brief and try to close the door again before anyone has the chance to get upset. Remember, under threshold is our buzzword. Or buzzphrase, if that’s a thing.

Again, treat this like it’s their initial meeting and they’ve never seen each other before. If things go well you can let them sniff each other. Reward with praise and treats.

Always be prepared to intervene and go back a step or two if needed.

You can always lure one of the cats away with a piece of string to chase or rattle the treat packet if things look like they might get out of hand.

Once the cats are calmly sniffing each other and making soft eye contact (as opposed to staring, which would be hostile), you can start keeping the door open and place a dog gate or baby gate across for short periods of time.

A screen door would be ideal if you have access to something like that.

Carry on using positive reinforcement by feeding the high-value food.

Be prepared to lure one of the cats away if necessary, keep interactions short (a good few seconds is far preferable to a tense two minutes), and always try to end when things are going well so the cats remain in a positive emotional state.

Play is another good way to defuse tension and build up a positive association, so try to incorporate this into your daily routine too.

Continue with these steps until the cats are calmly spending time together and you can remove the physical barrier altogether.

#5. Manage the environment

If one cat is a bit more feisty than the other, or one cat is coping a bit better with the reintroduction process, you can always use a harness and leash to make it easier for you to control things if anything goes wrong.

Dog gates or baby gates can also be really helpful, although some cats will jump over them.

Remember, always watch for signs of fear, anxiety, or stress and if you see any behavior you don’t like, calmly and quietly remove the aggressor and separate the cats again.

#6. Supervised interactions

Whenever the cats are in the same space together like this, make sure they’re under close supervision from you to make sure things stay calm and positive.

Try to avoid anything going wrong by keeping interactions short, watching the cats’ body language, preempting things escalating, and ending on a positive note.

Keep feeding tasty treats to build the positive associations with each other and use play as well, so the cats have an enjoyable activity to do together.

A piece of string to chase or some sort of wand toy with feathers is ideal for this. You may want to let each cat have a turn though so things don’t get too heated.

I often play games with my cats like this and the others just politely sit and wait their turn while another cat has a go!

If you don’t manage to preempt and things start to go wrong, interrupt* the cats, remove the aggressor (if possible), separate the cats, and go back to the previous step before trying again.

Patience and consistency are key here.

Any time you can’t supervise the cats, keep them apart until you are confident they can be calm and relaxed together without showing any signs of fear, anxiety, or stress.

Above all, be patient – this process may take days, weeks, or even longer. But the end result will be worth it for happy, harmonious kitties.

*When I say interrupt the cats, I mean lure one of them away with a toy or scatter some treats in opposite directions for each cat to go after.

If you need to take more drastic action you can use a towel or a cushion and place it between the cats to create a visual and physical barrier and gradually drive them apart by gently moving the aggressor back with your barrier.

If it’s safe to do so, you can pick up one of the cats if he trusts you and you’re sure he will accept this. The last thing you want to do is get scratched or bitten.

#7. Provide plenty of resources

Make sure the cats have access to a variety of litter trays, food bowls, water bowls, sleeping spots, and scratching posts in a way that they don’t need to compete for them or feel like they can’t access them because the other cat is nearby.

This will help reduce any potential tension or competition.

If you have multiple cats, it’s doubly essential to have multiple resources, including one litter tray per cat plus one extra, several water bowls and feeding stations, and a variety of toys and scratching posts (diagonal/horizontal/vertical) made up of different materials (sisal/cardboard).

Also, make sure there are plenty of hiding places and high perches for the cats to retreat to if they need some time alone or away from the other cat.

This will give them a sense of control and security in their environment. The more relaxed everyone is, the less likely they are to feel the need to fight or display aggressive behavior.

By providing a wide range of resources and opportunities for individual attention, play, and enrichment, your cats will have less reason to feel territorial or competitive with each other and can focus on being relaxed around each other.

#8. Watch for signs of aggression

Aside from the more obvious signs of aggression I’ve already mentioned (see #2), you’ll need to be on the lookout for more subtle signals of aggression or intimidation.

These may include:

• Staring
• Blocking another cat’s access to resources
• Making another cat move from where he’s eating, sleeping, or resting

If a cat is being bullied by one of the other cats, he may go into hiding or stick to one area of the house. He might also be constantly vigilant, waiting for the bully to come and attack again.

The American Association of Feline Practitioners states that “aggressors can control access to food, litter boxes, resting and perching spots, and attention, and the victim usually becomes withdrawn.

“Both the aggressor and the victim may have undesirable elimination and other behaviors.”

This is obviously extremely stressful and if anything like this happens, you’ll need to revisit your introduction process.

How can I keep my cats calm once I’ve reintroduced them?

Once you’ve had a successful introduction and your cats are reliably being calm around each other you just need to maintain the status quo.

Positive associations

Make sure you continue building positive associations between your cats through the use of toys, treats, high-value food, and play.

This can be done individually or together, but make sure each cat is getting plenty of attention and interaction.

Avoid stressors

Try to identify and avoid any potential stressors such as loud noises, visitors, or changes in routine that could agitate your cats and lead to aggressive behavior.

Pay attention to body language

Observe your cats’ body language and be aware of any warning signs that one may feel threatened or aggressive.

Intervene before any negative interactions occur and try to redirect their focus onto something positive, such as a toy or treat.

Provide plenty of resources

Maintaining separate resources, as well as multiple hiding spots and perches, will ensure your cats feel like they have control over their environment and can retreat if needed.

This will decrease the likelihood of aggression or competition over resources.

Environmental enrichment and mental stimulation

Stimulate your cats’ natural hunting instincts with interactive toys and puzzle feeders, or try adding cat trees or scratching posts to keep them mentally and physically engaged.

This will build confidence and the more they use their rational brain, the less extreme any emotional reactions are likely to be.

Pheromones

A Feliway diffuser releases calming pheromones for cats, mimicking the ones they produce themselves when they’re feeling happy and relaxed.

This can help reduce any stress or tension in the environment, making it easier for cats to get along.

You can use a Feliway diffuser throughout the cat introduction process and even afterward as needed to maintain a peaceful atmosphere in your home.

Note that Feliway may or may not be effective, depending on the cats, but it’s worth a try.

Cat music

Yes, you read that right! Some cats respond well to calming cat music such as Through a Cat’s ear, or even some classical music. 

What not to do if your cat introduction is not going well

There are a few things to avoid when you trying to introduce cats and ensure the best possible outcome.

Don’t punish the cats

This includes shouting and yelling or using aversive methods like spraying water, throwing objects, or, worst of all, a shock collar.

Anything like this that causes pain or fear risks a rapid escalation of aggressive behavior, can seriously damage the cats’ trust in you, and create a long-lasting negative association with the other cat that may be impossible to come back from.

Don’t force cats to interact or be close to each other if they’re not ready

You may be tempted to try and speed up the reintroduction process by physically forcing the cats together, but this will only heighten tensions and potentially lead to a negative or even dangerous encounter.

This is known as flooding. Flooding is a type of behavior therapy where an individual (or in this case, your cats) is exposed to an intense fear or anxiety-producing situation without making any effort to try to reduce the fear or anxiety.

The problem with this is there’s a high likelihood of failure because the cats will get even more fearful, anxious, or stressed.

As such, they may resort to other coping mechanisms, such as fighting or shutting down – where the cat displays no behavior at all until the situation has ended (Stilwell, 2022).

Don’t confine the cats in carriers

There was once a school of thought that confining one cat in a cat carrier and letting the other cat approach him to sniff, then switching them over, was a safe way to introduce cats.

The problem here is that the cat in the carrier has no control whatsoever and may feel completely unsafe. The last thing you want to do is add more stress to an already stressful situation.

The best thing you can do is keep up with positive, gradual introductions and provide a safe, enriching environment where your cats can thrive.

Don’t rub the other cat’s scent on him

You may see advice that suggests rubbing a towel on one cat and then rubbing it on the other cat in order to try and “share” scents.

The problem with this is that having another cat’s scent rubbed all over you, especially a cat you don’t even know, could be extremely stressful and unpleasant.

The goal is for these cats to be friends, so you want to be very careful not to create negative associations.

Don’t let them fight it out 

As I’ve said, the key is to watch the cats’ body language so you can be proactive and prevent fights from happening.

Cat fights can be dangerous and may cause nasty injuries that need veterinary intervention, not to mention increased stress for all parties involved.

If despite your best efforts, your cats get into a tussle, the most crucial thing you can do is break it up immediately. Allowing them to fight will only make matters worse.

Draping a towel or blanket over the cats will cause disorientation and, hopefully, cause enough of an interruption and distraction for you to be able to intervene.

You could also place an object like a broom or cushion between the animal and yourself.

The objective is not to hurt them but merely to create some sort of barrier so you can separate them without putting your hands or feet in the middle.

It’s normal for cats to not get along

Cats are territorial animals and will most likely need some time to adjust to a new presence in their territory.

The BSAVA Manual of Canine and Feline Behavioural Medicine points out that “many feline behaviours that are problematic for owners are in fact normal for cats.”

So first things first, it’s not your fault! If you’re trying to deal with a cat introduction not going well, know that it’s completely normal for cats to not immediately get along.

There’s research to back it up too. In a study of 2,492 people who owned multiple cats, 73.3% of them noted that there were conflict signs from the beginning when they introduced the cats.

The more cats that were in the house, the more frequent the conflict signs were (Elzerman et al., 2020).

“Cat–cat aggression when new cats are introduced is very common in multi-cat households,” confirms Daniela Ramos of the Canine and Feline Behaviour and Welfare Centre in Sao Paulo, Brazil.

According to Ramos, although aggression is usually caused by the resident cats towards a new cat, sometimes the opposite can happen.

“Unfortunately, many owners wrongly assume that cats, like humans, will be pleased to receive a new member in the group and get very frustrated when aggression occurs,” Ramos says.

“Cats, however, are quite unique in their social behavior, and are more likely to get on well with others when well socialized at an early age (2–9 weeks old), when environmental conditions allow and when they have been known to each other since a young age.” (Ramos, 2019).

A third study also reports that, among households with multiple cats, “half reported fighting between cats when the new cat was introduced.”

Although the researchers do point out that “approximately half of the people introduced the cats into the home by simply putting the cats together immediately.” (Levine et al., 2005).

This, although it can work, is definitely not advisable. If both cats are super mellow and cat social you could be successful with this strategy, but you’re here because things aren’t going well, so let’s press on with that.

Signs of conflict in cats

First of all, although it may seem obvious, let’s just recap how we know if cats aren’t getting along.

The study by Elzerman et al. (2020) found that staring was the most frequently observed sign of conflict in cats and that it occurred at least once every day in 44.9% of households.

This was followed by chasing, stalking, fleeing, tail twitching, hissing, and wailing/screaming.

Hissing occurred at least daily in 18% of the households, according to Elzerman et al. (2020).

Affiliative signs in cats

On the bright side, the researchers found that affiliative signs were observed more frequently than conflict signs.

In addition, physical contact between cats was observed at least once every day in around half of all multi-cat households, including “nose-touching, sleeping in the same room, sleeping while touching, and allogrooming.” (Elzerman et al, 2020).

(Allogrooming means the cats were grooming each other.)

Final thoughts

Overall, the key is to always monitor your cats’ behavior and intervene before anything negative occurs.

By providing a safe and enriching environment, your cats will be able to coexist peacefully and develop a more positive relationship.

But if all else fails and you’re still struggling with cat-cat aggression, it’s best to seek the help of a certified feline behavior consultant who can assess the situation and provide personalized guidance to improve your cats’ relationship.

In a worst-case scenario, you may want to consider rehoming or permanently separating the cats if that’s a viable option (Ramos, 2019).

For either of these options, give careful consideration to your cat’s stress levels and do your best to minimize them.

Remember, the well-being of the cats should always come first.

Hopefully, once you’ve followed the steps in this article, your cats will all be happy and purring in harmony without the need to resort to such drastic measures.

READ NEXT

Cats Fighting? Top Tips On How To Get Cats To Get Along

Resources

• BSAVA Manual of Canine and Feline Behavioural Medicine – Kersti Seksel
• Common feline problem behaviors: Aggression in multi-cat households – Daniela Ramos
• Conflict and affiliative behavior frequency between cats in multi-cat households – L. Elzerman, T. L. DePorter, A. Beck, & F. Collin
• Feline Behavior Guidelines – The American Association Of Feline Practitioners
• Flooding [Definition] – APA Dictionary of Psychology
• Flooding – Victoria Stilwell Positively
• Intercat aggression in households following the introduction of a new cat – E. Levine, P. Perry, J. Scarlett, & K.A. Houpt
• Understanding Cat Body Language | The Battersea way [Video] – Battersea Dogs and Cats Home

NEED HELP FROM A CAT BEHAVIOR SPECIALIST?

If you need more help dealing with a training or behavior issue, please find professional help from a certified feline behavior consultant. They will be able to offer you tailored advice for your cat(s) and situation.

Good places to start are:
- International Association of Animal Behavior Consultants
- COAPE Association of Pet Behaviourists and Trainers
- American Veterinary Society of Animal Behavior