How to Reintroduce Cats After a Fight | 5-Step Plan to Peace
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Introduction
It's upsetting when cats in a household start fighting and potentially hurting each other. These situations are stressful and tense for everyone involved. If two cats have been attacking each other, they should be separated to allow them time to calm down and then slowly reintroduced at a comfortable pace.
In this article, we will discuss how to reintroduce cats after a fight and all the ways to help create harmony in your home again, including:
- Why cats fight and if you should let them "fight it out"
- How to keep everyone in the household safe
- Why you shouldn't punish your cats for fighting
- A 5-step reintroduction plan on how to reintroduce cats after aggression
- How to recognize signs of tension (indicating to slow down with the reintroduction) and friendly behaviors (indicating you can move forward with the reintroduction)
- Environmental changes that will help successfully reintroduce cats
- How calming supplements and pheromones can help smooth the process
If you are unsure if your cats are playing or fighting, read How to Tell If Cats Are Play Fighting or Aggressively Fighting.
Why Are My Cats Fighting?
Common causes of fighting between household cats include:
- A new cat was introduced to the home and is viewed as a stranger in their territory.
- One cat went to the vet's or groomer's and came home smelling, looking, or acting differently.
- Misdirected aggression, for example, they are frustrated by an intruder cat in the garden or scared by a loud noise but redirect their frustrations toward their housemate instead.
- They reached social maturity at around two years old and no longer tolerate sharing their territory.
- There are not enough resources in the home, such as litter trays, resting spots, and feeding stations, which causes conflict.
- A young cat is irritating an older cat by trying to engage in play.
- One cat resents interacting as they are in pain, for example, due to arthritis or toothache.
Should You Let Cats "Fight it Out"?
Allowing cats to fight can result in serious injuries. It will rarely settle the conflict and likely only exacerbate the problem. With each fight, more stress, anxiety, and tension is created, leading to an increased likelihood of another fight breaking out and a decreased chance of a harmonious resolution.
An initial separation followed by a slow reintroduction is essential, in which you observe your cats behavior and adjust the approach accordingly to create a positive experience for both.
Prioritizing Safety
Do not handle fighting cats, as they are likely to redirect their aggression toward you, and you may get bitten. Instead, try to stop cats fighting by placing a large blanket, cushion, or piece of cardboard between them and herding them away from each other, or throw a large thick blanket over the aggressor so the victim can run away.
After a fight, cats should be separated and left alone to calm down. It may take hours or days for them to no longer be in an aroused state.
During the reintroduction process, we minimize the risk of a physical fight by moving forward in a slow and controlled manner, initially having barriers in place, and never pushing cats beyond their limit or leaving them alone unless supervised.
Do Not Punish Your Cats
Telling your cats off or spraying them with a water bottle when they fight is not recommended. They are already in a heightened state of stress and arousal, and punishment will only further increase their fear, anxiety, and possibly aggression, exacerbating the behaviors we are trying to eliminate. Instead, try to keep your voice and body language calm.
Consult Your Veterinarian
It's important to rule out pain, cognitive changes in older cats, or other health conditions as a cause of aggressive behavior. Your veterinarian may also refer you to a veterinary behaviorist who can assess your situation and make specific recommendations. If there is no cat behaviorist in your area, a good solution is to do an online consult.
Even with persistence, effort, and the best of intentions, some cats may never get along well, and a professional can also advise you if it's in both cats' interest for one of them to be rehomed.
Be Patient and Reintroduce Cats Slowly
It's important to be prepared that reintroducing cats after a fight can take weeks or months. Each step of the reintroduction process gradually increases your cats integration with each other. Their behavior will dictate the pace you should go, and only once they are both relaxed and comfortable should you move on to the next step.
Moving too quickly through the steps can result in aggression, which will set the reintroduction process back. You may previously have introduced cats without difficulty, but all cats have unique personalities, temperaments, and interactions with each other, and if two cats are fighting and hurting each other, then this reintroduction must be done with care and perhaps slower than you think.
Your cats may never be best buddies, but hopefully, with patience and consistent positive experiences, they will be able to comfortably tolerate each other.
Recognizing Signs of Tension in Cats
Learning to recognize subtle signs of tension is imperative for a smooth reintroduction process, as it allows you to separate your cats before the interaction progresses to a physical fight. If one or both of your cats' body language suggests they are uncomfortable with a situation, you will know to slow down the reintroduction process or take a step back. However, if unrecognized tension is overlooked and builds up, it could easily escalate into a fight.
Many owners perceive that their cats get along well, but actually, they just tolerate each other. After some consideration, owners may realize their cats were displaying subtle signs of tension that eventually escalated into physical altercations.
- Groom each other
- Greet each other with their tails up and sometimes a chirp
- Rub their chin, cheeks, or body on each other
- Sleep and resting with their bodies touching
- Relaxed while nose touching
- Staring at each other
- Tails swishing
- Dilated pupils
- Ears back or flattened
- Hiding
- Keeping distance
- Running away
- Looking down or away to avoid eye contact
- Blocking access to a resource or area, such as sitting next to the litter box, a doorway, or in front of the stairs
- Forcing one cat to move from where they were resting or eating
- One cat may need to sneak around to access the food
- Cats may lay near each other but not touching
- Chasing
- Hissing
- Growling
- Yowling
- Spitting
- Biting
- Swiping and scratching
- Posturing, such as arching their back and presenting their side
- Piloerection (hairs stand on end, and they look puffed up)
- Physically fighting with their claws out
- May find clumps of hair indicating a fight took place
Calming Supplements, Feline Pheromones, and Drugs
Calming supplements can be administered to help smooth the reintroduction. Feliway Optimum, a diffuser that releases feline-appeasing pheromones, can also be used throughout the home.
For more extreme cases, fluoxetine (Prozac), an anti-anxiety medication, can be tried for one or both cats depending on your vet's assessment. However, it can take up to 4-6 weeks to see the full effects.
- Feliway Optimum: releases a complex of calming feline pheromones into the environment, which can help reduce aggression between cats.1 Place them in the rooms where your cats spend most of their time.
- Zylkene: contains alpha-casozepine, a peptide derived from milk protein, with calming properties.2 The capsules can be opened and mixed with a small amount of wet food or an irresistible treat, such as Churu Lickable Purée Treats.
- Anxitane: palatable chewable tablets that many cats take like treats. They contain L-theanine, an amino acid found in green tea that promotes relaxation.3
- Purina Calming Care: contains the probiotic strain Bifidobacterium longum (BL999), which may help maintain calm behavior, likely due to influencing the gut-brain axis (communication between the gut and the central nervous system).4
- Royal Canin Calm Cat Food: contains tryptophan, a precursor for serotonin, which promotes a feeling of well-being.5
| Product | Empty | Features | Price |
|---|---|---|---|
 | Feliway | Feliway Optimum Pheromone Diffuser
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 | Zylkene |
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 | Anxitane |
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 | Purina Pro Plan Calming Care |
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 | Royal Canin Calm Cat Food |
| View on AmazonView on Chewy |
Creating a Positive Home Environment
During the reintroduction plan, it's essential to make environmental changes that will help minimize conflict between your cats. If adjustments aren't made, stopping the cat fights may be impossible.
Creating a positive environment includes the following:
- Multiple resources. Plenty of resources must be provided within the home, including food and water bowls, litter boxes, scratching posts, and areas for sleeping, hiding, and resting. Multiple resources are necessary to avoid competition and unpleasant interactions, such as being ambushed while going to the toilet, being prevented from accessing food, or being forced to leave a resting spot.
- One per cat + one rule. A helpful rule of thumb for each resource is to provide at least one per cat plus an extra one to reduce competition.
- Spread resources out. All resources should be spread throughout the house so each cat can easily and safely access them. Ideally, provide each cat with their own set of resources in separate areas of the home, which helps create a sense of ownership and security. For example, do not place litter boxes next to each other, as they will be viewed as one litter box, which can create competition and tension. In addition, water bowls, food bowls, and litter boxes should not be adjacent to each other since cats naturally toilet, eat, and drink in separate locations to avoid contamination.
- Avoid cats getting cornered. To avoid a cat becoming trapped or forced into close contact with another, there should be more than one exit/entry point to a resource or key area.
- Elevated platforms. Making use of the vertical space, such as by installing cat shelves (with more than one escape route) or providing cat trees, may help cats avoid each other if needed. They also increase a cat's perception of the amount of territory they have and function as lookout areas where they feel safe and can view their surroundings.
- Separate feeding stations. Cats will often eat next to each other if forced to, but they are naturally solitary hunters and feeders. Being forced to eat next to a cat they don't get along with can be stressful. Therefore, prepare the food in the kitchen without your cats present to avoid creating tension, and then feed them in separate areas.
- Physical and mental activities. Provide plenty of opportunities for physical and mental stimulation. Regular playtime with fishing rod-type toys, such as Da Bird, that bring out their inner hunter will keep them physically stimulated, and help them release their frustrations and aggressions. There should also be cat trees and shelves throughout the home. Providing food in puzzles, such as Trixie Puzzle Feeders for Cats, will help keep them mentally stimulated.
- Reduce stranger cats in the garden. Feed strays elsewhere, remove bird feeders, install a Motion-Activated Sprinkler in the yard, block their view using Frosted Glass Window Film, extend the height of the garden wall with trellis, and move resources away from windows so they don't feel threatened while eating, sleeping, and toileting. Cat-proof fencing, such as Oscillot, can also be considered, which will allow your cats to enjoy the safety of your garden, and although it may not prevent other cats from getting in, usually, they will not return once they realize they can't get out again until someone releases them.
| Product | Product | Features | Price |
|---|---|---|---|
 | Trixie |
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 | Da Bird |
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 | shelves | CatastrophiCreations Gardens Set
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 | Tree |
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| Product | Empty | Features | Price |
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 | Orbit | Orbit Motion-Activated Sprinkler
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 | Frosted |
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 | Barrier |
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 | Scat |
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 | SureFlap |
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5-Step Reintroduction Plan
Step 1. Complete Separation (Time to Cool Off)
After a fight, cats will require a period of complete separation to allow them to calm down. Separation is also important for preventing injuries and further damaging their relationship.
Cats should be separated for as long as it takes them to cool off and relax again, usually at least 48 hours. However, cats who are highly aroused from living with another cat with whom they've had ongoing conflict and tension often require a more extended period of separation, such as 5-7 days.
Your cats must be separated by a closed door so their ability to hear, smell or see each other is significantly reduced. Draft protectors can also be used if there is a large gap at the bottom of the door. Depending on the layout of your home, one of the following methods can be used to create each cat their own comfort zone:
- Divide the house into two areas (separated by a shut door)
- One cat is kept in a large room, while the other cat has the rest of the house (the cat kept in the large room can be the one who tends to be more aggressive, so they don't think they have driven the other cat away, or the one who tends to be timider if they would feel more secure in the room)
- Each cat is kept in their own single room (this may be necessary if either one is showing aggressive behaviors around the shared door)
If possible and practical, they should ideally be kept in the space they usually gravitate towards and where they feel safe. They must have all the necessary resources, including food, water, litter trays, scratching posts, toys, perches, hiding places, and bedding.
Creating a positive experience during this cooling-off period is essential, so each cat should have regular play and petting sessions. During this time, you should also make positive environmental changes to the home, and consider calming supplements and feline pheromones, as discussed above.
Positive Signs
Both cats are relaxed, playful, and comfortable, indicating they are ready to move on to the next step.
Negative Signs
Either cat is showing aggressive (hissing, growling, swatting) or fearful (skittish, hiding) behaviors, indicating they are not ready to move on to the next step. They may need a more prolonged separation or to both be placed in their own room (so there is no shared door).
Unfortunately, if either cat is agitated by the other's presence behind a door, this could indicate a poorer prognosis for resolving their aggressive behavior.
Step 2. Scent Swapping
Once both cats are calm and relaxed, scent swapping can begin. Scents should not be exchanged while the cats are in a heightened and tense state, as we want to swap calm and friendly pheromones, not fearful ones.
Once a day, gently rub cat A's cloth on cat A, then leave it with cat B, and gently rub cat B's cloth on cat B and leave it with cat A. When rubbing, focus on the cheek area and the base of the tail. Offer the cloth to the other cat paired with their favorite treat to create a positive association.
Once both cats have a positive or neutral reaction to the cloth, you can start to rub both cloths on both cats and continue to swap them, so not only are they exchanging scents, but their scents are mingling. Treats can also be offered to each cat while they are gently rubbed. Take care when rubbing a cloth onto a cat with the smell of another in case they have a hostile reaction.
If either cat won't accept having a cloth rubbed on them, rotate bedding and blankets daily instead, while ensuring they have an additional place to sleep and rest in case they are uncomfortable with the other cat's scent. Hopefully, over time they will rest on the bedding with the other cat's scent.
It can also be helpful to start clicker training your cats during this time, which can be used later to disrupt tension between the cats, refocus their attention on you, and positively reward them for a preferred behavior. In addition, it also provides mental and physical stimulation, and makes an excellent bonding experience.
Cat School Clicker Training Kit
- Teach each cat to touch their nose to a target stick or your hand to help redirect their attention away from each other
- Teach each cat to sit or stay to help keep them in one place during the reintroduction process
- Teach each cat to fetch a toy or a treat to help redirect their attention and move them away from each other if needed
- Use the clicker to reinforce calm behavior, such as sitting quietly or grooming themselves, to help teach your cats to relax in each other's presence
Positive Signs
Relaxed in the presence of the cloth, such as rubbing their chin or body on it, sleeping or resting on it, being content when stroked with it, or having no reaction to it, indicating you can move on to the next step.
Negative Signs
Moving away from the cloth, hissing or growling at it, or being agitated while being stroked with it, indicating they are not ready to move on to the next step. They need more time to build a positive association with the cloth.
Step 3. Space Swapping
Each day, switch both cats between their two separate spaces. For example, if the house was separated into two halves, swap who goes in which half each day, or if one cat was in a single room and the other cat had the rest of the house, alternate who roams the house while the other stays in the room. If both cats each have their own room, alternate who can roam the rest of the house each day while the other stays in their room.
Ensure your cats do not see each other while they are swapping spaces. This may mean taking turns moving cats between rooms and shutting doors until they are in their correct locations.
Positive Signs
Explore each space in a relaxed manner and are unphased by the other cat's smell, indicating they are ready to move on to the next step.
Negative Signs
Apprehensive and vigilant when exploring the space or showing signs of aggression or fear near the shared door, such as stalking, hissing, or fleeing, indicating they are not ready to move on to the next step. Continue rotating between spaces, remembering it may take weeks for them to settle, or go back to step 2.
Step 4. Visual Contact With a Barrier
Two people will be required for the next steps, with one person per cat.
- Install a screen door in the doorway that currently separates your cats, so they can see each other but can't physically interact. Ensure the barrier is secure.
- Begin at a distance from the doorway, which will depend on the size of the rooms in your house, but ideally, each cat should be 4-5 meters away.
- Give each cat their favorite treat or a small amount of delicious wet food. If they are not food-orientated, play with their favorite toy. High-value incentives are essential to help create a positive association with the other cat's presence, which should be reserved only for these training sessions.
- This first session will be short and should aim to end on a positive note. Once each cat has had their treat, food, or play, close the main door so they can no longer see each other.
- If one cat won't eat or play, move further from the screen door or end the session. In case they are simply not hungry, next time, withhold food for a few hours prior.
- Repeat these sessions across the screen door several times a day. If both cats are relaxed and comfortable, gradually decrease the distance and increase the duration by offering a larger volume of food or having a longer play session. However, only move closer once there have been at least two positive sessions at that distance.
- If one of the cats feels uncomfortable at any point and wants to move away, allow them to do so.
- Eventually, the cats should be approximately 1 meter from the door while happily accepting food or playing. It's unnecessary to ask your cats to be right next to each other, as doing so can make them nervous.
- Go slowly, watch for signs of tension, and don't push your cats beyond what they are comfortable with. Aim to end each session positively. If aggressive or fearful behaviors are shown, separate them for 24-48 hours, then continue, but from a greater distance from where the aggression was triggered.
If you need more control over your cats, they can also be trained to use a leash and harness. However, they will need to be acclimatized to the harness before the introduction, otherwise, they will likely be overwhelmed.
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 | Screen Door |
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 | Churu | Churu Lickable Treats for Skin and Coat
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 | Holster |
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Positive Signs
Both cats are relaxed and interested in eating and playing as they gradually move closer to each other, indicating they will soon be ready to move on to the next step.
Negative Signs
One or both cats won't eat or play, appears anxious, repeatedly looks towards the door, stares at the other cat, swishes their tail, crouches, flattens their ears, attempts to run away, growls or hisses, indicating they are not ready for the next step. Either the training needs to continue with them further apart or use the same method but first with the door closed so they can't see each other.
If you cannot progress, you may need to backtrack a step or speak to your vet about medications (e.g., fluoxetine).
Step 5. Supervised Sessions Without a Barrier
Your cats can now be allowed out together for short sessions. Continue to build a positive association by offering them treats and playing games (with separate toys if sharing triggers aggression) in different parts of the house when they are near each other and relaxed. Initially, it's important to keep these sessions brief and conclude them on a positive note. Watch closely for signs of tension, indicating they should be separated.
If the sessions go well, gradually increase the duration and frequency of the supervised sessions. If your cats remain comfortable, the level of supervision can slowly be reduced, although you should continue to monitor for signs of tension.
To give your cats the best chance of success, the positive environmental changes (discussed above) should have been made, including providing plenty of resources throughout the home and keeping outdoor intruder cats away from your property. In addition, consider placing a bell on the collar of the more aggressive cat, allowing the more timid cat to avoid them if necessary.
Positive Signs
The cats are tolerant of each other and ideally comfortable with each other. There is minimal stress and conflict, although occasional signs of tension may occur, such as hissing or staring. They may never develop a close bond, such as grooming each other and cuddling.
Negative Signs
The cats resume living in stress and fear of each other, with fights breaking out. You may have moved through the steps too quickly and have to return to step 1. Consult a veterinarian behaviorist if you haven't done so already, many of whom offer online consultations.
If the cats can't live in harmony and the situation is too stressful for them, sadly, you may have to consider rehoming one of them.
Summary: Cat Aggression and Reintroducing Cats After a Fight
- Housemate cats may fight due to reaching social maturity, one cat smelling or looking different (often after the vet's or groomer's), redirected aggression (such as a stranger cat in the garden), a medical condition (such as pain), a lack of resources, or the introduction of a new cat.
- Consult a veterinarian to rule out medical causes of fighting, who may also refer you to a veterinary behaviorist.
- Never let cats "fight it out" or punish them for fighting, as this will only worsen the situation.
- Do not try to handle a cat during a fight or soon after, as they may redirect their aggression toward you. Instead, separate a fight by placing a large blanket, cushion, or piece of cardboard between them and herding them away from each other, or throw a large thick blanket over the aggressor so the other cat can run away.
- The step-by-step reintroduction plan has five stages, each gradually increasing your cats' comfort level with each other, starting with a complete separation, then scent swapping, moving on to space swapping, followed by visual contact with a barrier, and finally, supervised sessions without a barrier.
- Highly-valued rewards, such as treats, delicious wet food, or toys, should be used throughout to help your cats create a positive association with each other.
- The reintroduction plan will take time, possibly weeks or months, and it's important to be patient.
- Observe both your cats' body language and learn to recognize subtle signs of tension, which is imperative for assessing if they are comfortable with each stage of the reintroduction plan, and if you need to take a step back or if they are ready to proceed with the next phase.
- Use calming supplements, pheromones, and possibly anti-anxiety medications to help smooth the reintroduction process.
- It's essential to create a positive environment, such as having plenty of resources throughout your home and stopping stranger cats from intruding into your garden if the reintroduction process is to be successful.
References
- DePorter T.L, Bledsoe D.L, Beck A, & Ollivier E. (2019). Evaluation of the efficacy of an appeasing pheromone diffuser product vs placebo for management of feline aggression in multi-cat households: a pilot study. Journal of Feline Medicine and Surgery.
- Makawey A, Iben C, Palme R. Cats at the Vet: The Effect of Alpha-s1 Casozepin. Animals (Basel). 2020 Nov 5;10(11):2047.
- Dramard V, Kern L, Hofmans J, Rème CA, Nicolas CS, Chala V, Navarro C. Effect of l-theanine tablets in reducing stress-related emotional signs in cats: an open-label field study. Ir Vet J. 2018 Oct 9;71:21.
- Colorado State University Study EvaluatesProbiotic for Calming Effects in Cats
- Landsberg G, Milgram B, Mougeot I, Kelly S, de Rivera C. Therapeutic effects of an alpha-casozepine and L-tryptophan supplemented diet on fear and anxiety in the cat. J Feline Med Surg. 2017 Jun;19(6):594-602.
