Aggressive cat behavior toward other cats is very common. According to recent research, 87,7% of cats’ households reported aggressive behavior. The 9 most common causes of cat-to-cat aggression are as follows:
- Pain-induced aggression,
- Aggression due to a lack of socialization,
- Fear-induced aggression,
- Play Aggression,
- Status-related aggression,
- Territorial aggression,
- Maternal aggression, and
- Re-directed aggression.
- Is one of your cats acting aggressively toward the other cats in your house?
- Are you wondering why your cat becomes aggressive all of a sudden?
- You want to adopt a new cat but you are worried that your resident cat will attack the newcomer?
Your concern is justified. Aggression among cats in the same household is pretty normal. A 2019 study looked at signs of aggression in multi-cat homes.
The survey was sent to cat owners who had two or more cats. Only 12.3% of those polled said their cats have never shown symptoms of conflict.
The remaining 87.7% reported that their pets showed aggression as detailed below:
- 73% The aggressions start at the beginning of a new cat introduction.
- 24% The cat’s behavior gradually changed.
- 3% The cat’s behavior changed abruptly.
These percentages provide us with some key considerations:
You should plan accurately any new cat introduction.
Since peace in your cat’s family can vary over time, you need to understand the underlying causes to restore it.
If you landed on this post, I’m guessing one of your cats is acting aggressively and you need some actionable tips to tackle the problem.
As you may know, cat aggression is one of the most difficult issues to address since it takes a lot of time. Conflicts between cats, however, can be handled.
This article will teach you why your cat gets aggressive, the different types of cat aggressiveness, and how to cope with the issue, among other aspects. Read until the end and you’ll be able to manage your cat’s conflict better.
Let’s dive into it:
Why Do Cats Fight Each Other?
Inter-cat aggression, like human aggression, is not triggered by a single source. This means you need to understand normal cat social behavior to prevent these episodes.
So why do cats become aggressive toward other cats?
Here are some common triggers:
- A new cat was adopted.
- Cats’ personalities clash.
- Lack of early socialization.
- Small changes in the daily cats’ routine.
- Illness or medical condition that causes pain.
- Moving or changing the position of the furniture.
- Cats reach social maturity and are not spayed or neutered.
Other factors can also trigger aggressive behavior:
- Physical size (large cats often intimidate smaller ones).
- Activity (active cats intimidate more quiet cats).
- A lack of pleasant social experiences with other cats.
- A one-time event that triggers aggression.
- Genetic factors (friendly parents are more likely to produce friendly offspring).
Domestic cat aggression is a natural aspect of predatory behavior, play, and social strife. Cats, as solitary hunters, avoid physical confrontation at all costs. Why? Because any fight might result in injuries, inability to hunt, and, ultimately, death.
Cat communication, which includes vocalization, body position, facial expression, and scent-marking, is mostly used to avoid violence and relieve stress.
Felines typically show their social rank by posturing and “bluffing” messaging that does not result in damage. They can often learn to tolerate or avoid one other if they get along.
Fighting will happen, however, if:
- The particular circumstances dictate it as the only option, or
- The aggressor is confident that the opponent will not retaliate.
As the victim cat begins slinking around, bullying the lowest-ranking cat—often an elderly or infirm kitty—can grow rampant. Using weak body language and hiding is a bad approach since it promotes further bullying.
Aggressors can limit the victim’s access to food, litter boxes, resting, perching areas, and attention. In those cases, the victim will normally retreat. The conflict between your cats might cause various symptoms such as:
- Not eating,
- Over-grooming,
- Hiding and fleeing, and
- Not using the litter box appropriately.
Even mild forms of aggression, if not addressed, can evolve into serious aggression. It is important to assess and tackle any change in the cats’ interactions and behavior right away.
Let us now examine the subtle and not-so-subtle signals that aggressive cats exhibit.
How Do House Cats Show Dominance?
Overt Aggression
Cat overt aggression is easy to spot since hostile behavior is clear. Fighting, chasing, striking, biting, and swatting are all examples of cat aggression.
To prevent them, remember these signs that precede the aggression:
- Raising the back hairs,
- Wagging the tail from side to side,
- Showing offensive body posture, and
- Vocalizing (hissing, growling).
The aggressor will also show his or her dominance by spraying and scratching furniture. Some dominant cats even engage in “power grooming,” vigorously licking another cat to get it to go away.
Covert Aggression
Cat covert aggression is more difficult to detect. The aggressor will try less evident methods to keep its victim away from important resources. Food, water, litter boxes, and resting locations are the source of the attention.
Among these behaviors are:
- Staring,
- Blocking thoroughfares,
Laying in the middle of the room, - Blocking access to an indoor litter tray,
- Resting in the highest place of the cat tree,
- Marking all the favorite areas of the “victim”,
- Sitting directly in front of the cat flap to deny entry/exit.
The aggressor will also focus on denying the “victim” any human attention.
This is often quite subtle since the cat simply has to place itself between the other cat and the resource to block access. To the casual observer, this seems to be a cat taking a nap in a completely safe place.
Meanwhile, the victim will be peeing and pooping in other inappropriate areas. Litter box issues are one of the first signs hinting that one of your cats is getting bullied.
Here are some sample scenarios to help you detect less evident behaviors.
Samples Scenarios
| Overt Behavior | Covert Behavior | |
|---|---|---|
Aggressor | A confident cat hackles up another cat when resting in his favorite bed. | A confident cat displaces, steals, and harasses lower-ranking cats' bedding, toys, and food, followed by facial gland marking. |
A confident cat chases and attacks the target with its teeth, accompanied by vocalization. | A confident cat stares when the victim enters the room. | |
Victim | A less confident cat exits the room or backs up and withdraws into a smaller space, tail tucked and vocalizing. | A less confident cat marking with facial glands in places where the cat has been exiled. |
A less confident cat reacts by hitting or swatting while retiring or avoiding further pursuit. | A less confident cat marking with urine and feces "boundaries territories" where he has been displaced. |
Understand Cat Body Language
Offensive Body Posture
An offensive cat will try to intimidate the victim by choosing a posture that makes him look bigger.
A more offensive and aggressive cat may have its ears pushed back and its pupils constricted. Its tail may be up or down with fur standing on end.
Defensive Body Posture
The victim will try to become smaller to avoid conflict. The cat may seem nervous, scared, and easily startled, trying to run and hide.
A fearful cat may exhibit dilated pupils, backward ears, or a lowered tail, tucked in between its legs.
They can growl, hiss, howl, or meow in either instance (aggressor or victim). These vocalizations might signal their distress.
What Causes a Cat to Become Aggressive?
Male and female cats can get hostile toward other cats for many reasons. While some clashes are obvious, others are so subtle we usually miss them until we start seeing some wounds.
Domestic cat aggression is more nuanced and intricate than fights between two cats outdoors. The following are the most common reasons for animosity in domestic cats:
# 1 Pain-induced Aggression
When cats are in pain, they become aggressive. They‘ll try to avoid touch since it might worsen the pain.
The same goes in the case of mental illness since the suffering is caused by an illusion of pain that comes from the mind.
Also, keep in mind that cats are “genetically” built to hide that they are in pain.
If your cat suddenly behaves aggressively, it could be a sign of a medical problem.
Triggers
Any medical issues that may cause pain. Some frequent issues are the following:
- Hyperthyroidism,
- Osteoarthritis,
- Dental diseases,
- Diabetes,
- Liver diseases,
- Broken bones,
- Hormone imbalances,
- Urinary tract diseases, and
- Neurological issues.
Consult a veterinarian as soon as you suspect that your cat is in pain to ensure its health.
Once the vet rules out any medical problem, you can start working on identifying other causes of the aggression.
Doing so requires you to develop a behavior modification plan with your veterinarian or a behavioral expert.
# 2 Aggression Due to a Lack of Socialization.
A lack of pleasant experiences with other cats before 3 months of age may result in an absence of normal responses to other cats.
If your cat grew up as a unique pet, it may have a negative reaction the moment you introduce it to a new cat.
Why?
Because it’s afraid of the unknown, it lacks social feline skills, and it dislikes getting its routine disrupted. Also, it will feel no pleasure in sharing territory, food, and affection.
These cats can become extremely hostile if forced into intimate contact with other cats.
Triggers
These cats will never be typical, cuddly buddies for other cats. Although they are friendly toward people, they will find it difficult to accept other pets into their household.
To mitigate this, you need to find a way to make it start liking the other cat. As a result, they will gradually start ignoring one another.
However, this strategy may not always be effective. In certain cases, rehoming the cat is the most humane thing to do.
# 3 Fear-Induced Aggression
Fear aggression occurs when a cat is attempting to protect himself from an attack it believes there is no escape from. This sort of hostility happens when a cat comes into contact with an unfamiliar cat.
According to feline behavior experts, scared responses may be inherited as well. Cats could be genetically friendly or shy. So despite the best socialization, a shy cat will become aggressive whenever he or she is afraid.
Regardless, if threatened, any cat will defend itself.
Fear aggressiveness can emerge in families of cats that have previously gotten along nicely. It might happen if one of the cats unintentionally associates the other cat with a negative event. For example, a thunder scared him just when the other cat was approaching.
Remember: Any intervention that makes a certain cat feel trapped may worsen its fear-aggression. In fact, constraining two cats to be in each other’s presence without the option of escaping would aggravate the scared animals. This method does not work on cats.
Triggers
An unpleasant experience associated with a family cat.
Introduce the cat to the frightening scenario gradually. This method is known as desensitization and counterconditioning.
For example, you may offer the timid cat a really tasty reward while introducing the new cat from a safe distance. When the fearful cat starts eating, you can slowly reduce the distance.
You may also use a synthetic pheromone diffuser, such as Feliway, to quiet the cat. When it comes to medications, use them as last resort and always follow the veterinarian’s advice.
Never medicate your cat alone.
# 4 Play Aggression
Cat play aggression is more often directed at humans, but can also happen in inter-cat relationships. As stated earlier, this is typical behavior in cats lacking social skills.
It usually happens to those separated early from their mother. They may not have learned to sheath their claws or inhibit their bite.
Normal cat play consists of pouncing, batting, and chasing. And when the play becomes too rough, well-socialized cats deescalate. Only when arousal of vigorous play turns into a quarrel, do problems arise.
Owners who are unfamiliar with typical cat play may interpret it as “fights” even when neither cat is harmed.
You can tell if they are playing or fighting by interpreting their body language. If there are no vocalizations, such as growling or hissing, you can stay calm.
Instead, if you hear some weird sounds and one of the cats flees, you are most likely dealing with play aggression.
Triggers
Veterinarians and behaviorists recommend adopting both the kitten and the mother, or two kittens at the same time, if possible.
At any suspect your cats are playing too rough, stop them in the early escalation phases.
Roll many balls past the cats, call them, walk to the kitchen, use an electric can opener, or have family members divert the cats in different ways toward human-interactive play.
To keep cats entertained, have many interactive toys around the house, and switch them regularly.
Finally, play with both cats on a constant schedule, preferably 2-3 times each day.
# 5 Status-Related Aggression
Cats in stable social families form dominant relationships. If the cats are very friendly and gregarious, these interactions may be so subtle the average owner is unaware of them.
It is common among mixed-sex roommates.
When cats become socially mature (somewhere between 2 and 4 years old) they begin to challenge other cats. Problems occur when one cat of the group does not accept the imposition of the other.
Conflicts are sometimes obvious but not problematic. For example, when all the cats, including the youngest, yield to the alpha cat. Unless provoked, the latter will not act aggressively.
However, dominant relationships may be problematic at times. This can happen when the alpha cat starts guarding the house’s resources for long periods of time.
Even if it has no need to use them. For example, waiting for hours next to the food dish or at the entrance to the only room in the house with litterboxes.
Bully cats show extreme dominance and violence toward lower-ranking cats. The situation is worsened if the low-ranking cat signals submission and attempts to avoid contact.
Triggers
Cats who were mistreated as kittens due to a lack of resources such as food.
The first step is to neuter or spay the cat. According to studies, this alone may drop 90% of aggressive behavior.
If your cat continues being hostile, the easiest approach is to ensure that essential supplies are available. Place more food stations, water, litter boxes, and resting places around the house.
The alpha won’t be able to guard them all at once. There are two more recommendations you can put in place.
The first one is close monitoring of social interactions and, if possible, recording them when they are along.
The second one is constantly interrupting any bullying event. If you are not able to supervise them, keep them separated in different rooms.
# 6 Territorial Aggression
Cats, as solitary hunters in the wild, seldom leave their hunting areas once established. Going beyond their territory exposes them to other cats and other animals with which they compete for food and who may hurt them.
Domestic cats feel safe and secure in their home for the same reason. They know they are not in danger and have access to all the resources they need to survive and grow.
For them, consistency is more important than change. This is especially true if the change entails the introduction of a newcomer to your cat’s well-established territory.
Cats also have their personalities. While some cats are used to overlapping others’ territories, others prefer keeping a good distance from their neighbors.
Domestic cats, even if they have unlimited resources, feel the same way. Although territorial aggression is slightly more common in male intact cats, female cats are not exempted.
This sort of aggression includes pursuing and ambushing the intruder, as well as hissing and swatting when contact occurs.
Triggers
If the aggression is aimed at another cat in the house, separate them and gradually reintroduce them. If the aggressiveness is focused on the cat outdoor, try keeping your cat indoors.
Provide a variety of interactive toys for your cat to play with so that he or she may spend his or her energy.
Playing with your cats 2-3 times a day can also help, as using synthetic pheromones to relax the cat.
Also if your male cat is intact, fix him or her as soon as possible.
# 7 Maternal Aggression
Aggression can occur in any family with females who have just given birth. These hot spots often appear passively.
Even though maternal aggression happens in female cats, some male cats will defend their kittens. Those proud dads won’t let any other cat near their nest!
Mother cats are protective of their kittens and will attack any cat that approaches them. Their instinct is so powerful they may seriously injure “curious” cats.
You see, their ultimate goal is to keep their kittens safe from any potential harm.
Triggers
When maternal aggression is present, there is no way to reprimand the mother cat.
The best thing you can do is to keep onlookers at bay. Provide a quiet spot for her and her kittens.
Also, you must not change the odor of the nest and handle the kittens as well.
# 8 Non-recognition Aggression
Cats communicate mainly by using their sense of smell, and the familiar communal odor that a group of cats creates helps them bond.
If one cat’s scent changes the group could react dramatically, refusing the cat.
A common scenario happens when one cat gets back home from the vet. The returning cat has gotten a combination of menacing and unpleasant odors the others dislike.
Worse, they may link the scent with prior negative encounters at the vet’s office. As a result, the returning cat may get attacked by the others since they do not recognize their buddy.
Triggers
Keep the returning cat in a separate room for at least twelve hours (or overnight). This way, your cat will enable to groom himself and re-establish his scent.
Consider rubbing him with a worn t-shirt or another piece of clothing to give him your smell.
# 9 Re-Directed Aggression
When a cat turns its aggressiveness at another cat that did not start the act, this is known as redirected aggression.
An external source, such as a startling sound or movement, or the sight of another cat through the window, causes the perceived threat.
However, the effects are aimed at the first object the cat comes into contact with (human, dog, or another cat).
This huge emotional reaction, known as fight or flight, causes the cat’s body to release adrenaline and prepare her for danger.
The attack might unintentionally target an innocent household cat that was in the wrong place at the wrong time.
Although it may appear as odd, redirected hostility can occur up to 24 hours following the trigger.
This form of aggression can wreak havoc on the cats’ relationships. Because the victim will come to dread or distrust the cat that attacked him, and the aggressor will link it with a negative experience.
Triggers
Leave the aggressive cat alone to settle down. Separate the two cats at first, regardless of whether one is the victim or the aggressor.
Then gradually reintroduce them (the same way a new cat is introduced into the household).
It may be useful to remove stimulus from their everyday routine. Allow them to have enough exercise to burn off the extra energy that causes these occasional episodes.
If a stray cat is the “trigger,” for example, lower a window shade, install a curtain or stop feeding stray cats in your backyard.
How to Stop Aggression Between Cats
There is no ‘quick fix’ for aggressive behavior. Although we have already talked about what to do in each specific case, in this section we will cover the general rules of thumb to follow.
We’ll address both the recommended and discouraged strategies.
DO’S
Use Smell to Familiarize the Two Pets
Use the powerful cat’s sense of smell to control aggressive behavior. Cats can learn about each other by employing scents. You can use a cat’s blanket.
Rub each cat with a blanket before placing it on the other cat’s bed.
Wipe the blanket over places with smell glands, such as the face, back, and tail.
In this way, even if they have never met before, they will begin to get to know each other.
They will feel confused at first since they can smell something “unfamiliar,” but they will also recognize their scent.
The “unfamiliar” odor will become “familiar” over time, and the distrust will fade.
Keep Cats Separated
Many cats prefer to play with you rather than food or catnip. Toys that mimic the hunted behavior are the greatest. To keep yourself safe from the claws and teeth, use wanded toys with feathers on the end, which they may pursue and pounce on. Give each cat individual attention. Then you may begin playing with both cats keeping them at a safe distance. Ideally, ask for help from a family member. Over time, reduce the space between the two cats and allow them to play together.
Playing with your cats will also provide them with an extra benefit: release built-up energy as well as keep them mentally and physically engaged. This will prevent boredom and disputes.
Schedule Playing With Your Cat Daily
Many cats prefer to play with you rather than food or catnip. Toys that mimic the hunted behavior are the greatest.
To keep yourself safe from the claws and teeth, use wanded toys with feathers on the end, which they may pursue and pounce on.
Give each cat individual attention. Then you may begin playing with both cats keeping them at a safe distance. Ideally, ask for help from a family member.
Over time, reduce the space between the two cats and allow them to play together.
Playing with your cats will also provide them with an extra benefit: release built-up energy as well as keep them mentally and physically engaged.
This will prevent boredom and disputes.
Give Cats a Reason to Like One Another
The association strategy is the most effective way to do this. Give the cats a reward whenever they are near.
You may create associations with food, play, or petting based on what they like the most. You must be consistent for this strategy to work.
As a result, the aggressive cat will realize that whenever the other cat comes, pleasant things will happen. And the “victim” cat will no longer fear or distrust the other cat.
Increasing the Number of Resources
Increase the number of toys, trees, litter boxes, resting spots, hiding places, scratching posts, feeding stations, and water bowls.
Follow the ratio of 1 per cat + 1 extra.
And remember to spread them around the house.
You will prevent the cats from vying for the same resources, and they will be able to avoid each other without conflict. Also, the aggressive cat won’t have the chance to control all areas at once.
It is critical to keep the litter box as clean as possible since both cats, the aggressor, and the victim will tend to mark their territory.
Spay or Neuter Any Cat in Your Home
Fighting is frequent among intact cats, and their behavior can have an impact on all your pets.
Cats begin to challenge others as they age socially. The alpha cat will not tolerate such behavior, and the harmony may break.
Consider spaying or neutering your young cat as soon as it reaches sexual maturity.
Use Synthetic Pheromones
Pheromones are special molecules that contain chemical messages. Products made with synthetic pheromones mimic those chemicals. Feliway® is the best known and recommended.
FELIWAY® contains a synthetic replica of cat pheromones along with a trace of catnip.
These components amplify their olfactory signals, which relaxes them and enhances their behavior. As a result, their interactions with other animals improve.
Use a diffuser while the aggression problem is getting solved.
Take Your Cat to the Vet
When cats are in pain, as previously stated, they become aggressive.
If your cat suddenly becomes aggressive, the first action should always be to contact your veterinarian.
Make your cat go through a complete medical checkup. Any behavior change might be an early sign of a medical concern.
Also, if your cat needs anti-anxiety meds, your Vet can prescribe them. Avoid giving your cat any over-the-counter medications without consulting the vet.
While medication is not a cure, it can improve the effects of behavioral therapy.
Contact a Professional Feline Behaviorist
Expert advice will help you in dealing with the situation more properly. It will give you the confidence to use the most suited strategy for your particular scenario.
If you’ve tried everything and still can’t get your beloved pets to stop fighting, consider rehoming one of them.
Remember that the most important thing is to make your cats’ lives better. Make sure they are happy regardless of where they live.
DON’TS
Never Physically Punish the Cats Involved
All you will do is increase their stress level, and they may feel compelled to fight you off.
You might aggravate the problem by making the cats involved become more reactive and learn that you are a threat.
Never Allow the Cats to Fight
Cats don’t solve their problems by fighting. Interrupt aggressive behavior as soon as the conflict begins.
The more they fight, the harder it will be to help them get along.
Never Reach Between Two Fighting Cats
Most cat owners have good intentions and want to separate fighting cats to prevent them from getting injured.
However, this puts them in danger. By placing yourself in the middle, there are higher chances of getting hurt.
Never Reach Between Two Fighting Cats
Most cat owners have good intentions and want to separate fighting cats to prevent them from getting injured.
However, this puts them in danger. By placing yourself in the middle, there are higher chances of getting hurt.
Should I Intervene When My Cats Fight?
Yes, you should act as soon as you notice them fighting. Your major goal, though, should be to keep everyone safe.
Therefore, avoid breaking the conflict by putting yourself in the front. Instead, try the following methods:
- Make a loud noise to distract them. Hit two pot lids or anything else that makes a disruptive noise. This will draw their attention to the source of the noise.
- Cover them with a large blanket. You’ll obscure each other’s line of sight, and the fight will end quickly. Also, this approach will allow you to carry and separate each cat easily.
- Use water as a last resort. Cats despise water and will run in the opposite direction to escape from it.
Are My Cats Playing or Fighting?
To determine if your cats are playing or fighting, pay attention to their body language and vocalizations.
Here is a checklist of things to look for:
- There is no hissing or snarling.
- There is no hair piloerection.
- The claws must be sheathed at all times.
- The ears should be kept mostly in their usual position.
- Any biting should be done gently and without causing pain or harm.
There is also an easy way to know whether they are just playing: their bottom backs should be up when pouncing each other.
But, if you notice growls, hisses, visible claws, bristling fur, and flattened ears, you should quickly separate them since the conflict is serious and might be harmful to both of them.
How Long Does It Take for Cats to Get Used to Each Other?
Cats, on average, take 8 to 12 months to build a peaceful relationship with another cat.
However, several situations might cause the general rule to be broken. The most significant are:
- The age of each cat.
The little ones easily get used to the newcomers. The younger the cat, the faster it will get along with other cats.
On the contrary, the older the cat, the longer and more difficult the process will be. - Whether they have been sterilized.
Hormones influence how they act in the presence of other cats. If both males and females are still intact, they are less friendly.The moment you sterilize them, they lose their territorial and sexual drives. Having your cat fixed will make him or her more social with other cats.
- Each cat’s personality.
Certain cats, like people, are shyer than others.
The more sociable cats will have less difficulty accepting new cats into their family group. Shy cats will take longer. - The cats’ gender.
Males take longer to “make friends” than females. This is because they live alone in the wild. They only meet other cats when they are mating, fighting for territory, or trying to conquer a female.
Domestic male cats follow the same behavior. Females, despite being territorial, are more tolerant of other cats.They get along more with other females because they help each other raise kittens in nature.
Also, they spend a large amount of their life with other females, usually their sisters.
In any case, even if they do not become best friends, they can learn to tolerate one another after some time.
Unfortunately, in certain rare cases, cats will never get along. And rehoming will be the only choice.
Conclusion
Dealing with aggressive cat behavior towards other cats is a big problem inside households.
Even if we love our pets with all our hearts, we should never put our safety and peace of mind aside.
Having said that, we must do everything we can to deal with cat aggression. Remember that if they act aggressively, it’s because they’re suffering.
In this post, we looked at the most common causes of aggressive behavior in cats.
We then looked at the two types of aggression: overt and covert aggression. And also covered how to spot aggression through their subtle way of communicating. Things that a normal pet owner would completely miss.
We investigated aggressive cats’ body language. And looked at the nine causes/types of feline aggressiveness, and how knowing them may help us develop precise and effective solutions.
Finally, we addressed the most essential advice on what to do and what not to do when trying to stop two cats from fighting each other.
My main goal was to provide you with everything you needed to start addressing the problem with more confidence.
Aggression between cats is a serious issue that must not be ignored thinking that it will get fixed by itself. If your first attempts fail, I recommend you consult with your veterinarian and a behavior specialist.
I can’t wait to hear your thoughts; please leave them in the comments section below.
The Cat Journey uses only trusted sources, including peer-reviewed studies. This is how we support the tips and information shared in our articles.
