There’s something strange when your cat hisses at every other cat it comes in contact with, especially if they used to be on good terms.

If your cats have always gotten along but now seem to be constantly at odds, you know there must be a reason. Sometimes all it takes is a little thought to figure out what that is.

We’ll go through some reasons your cats may hiss at each other. In addition, we’ll delve deeper into the possible causes of this behavior. 

Hopefully, with this knowledge, you will help them overcome their problems and reconcile their disagreements.

Why Do Cats Hiss?

You are likely to think that your cat may hiss for no reason. However, it may be because of a negative feeling like pain, anger, distrust, or everything altogether.

“Hissing is one of the sounds cats make that may mean something you are not thinking of, but it is a way to express repulsion”.  

They use it as a defensive warning to prevent a detected opponent. 

Why Is My Cat Hissing At My Other Cats All Of A Sudden?

Hormone Changes

Let’s face it: the power of hormone shifts is something that every human being can connect to.

You’re probably well aware of how unpredictable and bothersome they can be. Cats are no exception.

It could be a ruckus for a while if you have two teen kittens going through a huge transition.

Maturity in Sexual Relations

Cats of the same sex, in particular, may become aggressively territorial.

If you only have one cat who is sexually mature, he or she may be a little testy, which may deter other cats.

Assume it’s the hormones if the fighting doesn’t start until one of your cats is 6 months old.

New Factors Causing Stress

Stress has diverse effects on different animals, including your cats.

If something has changed around the house that makes your cat feel uneasy, they may take it out on their best friend.

Many causes can cause stress in cats, some of which may not be readily apparent.

The following are some possible reasons:

  • Newcomers

Whether it’s a human or animal baby, your cat might not be too happy about a new addition to the family.

Instead of venting their frustrations on the situation, they may get irritable with a friend.

When they come close, you might notice them acting tight and then snapping at the other kitty.

  • Changes in the Family

Your cat may be unhappy if you have recently moved or even moved the furniture. Sudden behavioral changes, such as fighting amongst each other, can occur.

  • Changes in Work Schedule

Did you start working a different shift, or perhaps more or less than usual, recently? Your pets might not be thrilled with the new routine.

Their lack of comprehension could lead to irritability, which could lead to fights.

  • Ruckus on the street

Has there been a lot of disturbance outside your house recently? They could be quite irritated by what’s going on.

Maybe a neighbor’s house is about to be remodeled, and they’ve been hearing saws all day. Alternatively, a local animal may irritate your cat.

If this is the case, your cats may become irritated with each other. However, it is most likely to happen while your cat is scanning the area.

Underlying Health Problems 

We’ve all experienced what it’s like to be sick. Some illnesses can be painful, and our cats don’t have the ability to communicate as we do.

As a result, an “ouch, that hurts!” could be misinterpreted as aggressiveness.

Other concerns, aside from pain, can also create negative reactions. Some neurological issues can influence your cat’s agitated reaction.


Your cats may have had the best of intentions, but they went too far. It’s likely that during play, one of them got a little rough, and now someone has the wrong idea. 

If it’s based on fear, there might be a back-and-forth right now—with a simple remedy.

 Issues of Dominance

Your cats may argue about who is in charge around the house. If you have a really domineering cat, it’s possible that things will get out of hand at some point.

It’s natural for some cats to be more dominant than others, but it has to be balanced.

If your cat is hissing at other cats, one of the most common reasons is because he is in pain.

If your cat isn’t feeling well, they may not want another cat around to aggravate the situation.

If you have an elderly cat who is developing arthritis, they may not want another cat to get close to them for fear of being injured.

It could be a visible wound on the surface or something within that isn’t visible.

Of course, it’s possible that they’re not in the mood to play. If you have an older cat and a younger cat, it’s possible that their energy levels are incompatible.

If you have a sneaking feeling that it’s because of pain, make an appointment with your veterinarian.

When both of your cats hiss at each other regularly, it’s not a relaxing setting. Seek the source of the problem, especially if you believe it requires veterinary help.

Sudden fighting is unusual, but with the right measures, it may be managed. You can put an end to the situation after you figure out what’s bothering your furry buddies.

Types And Causes Of Feline Aggression That May Make My cat hiss At My Other Cats

If your cat is acting aggressively for no apparent reason, one of the following factors could be at play:

Fear Aggression 

When your cat feels frightened or trapped, he or she may exhibit fear aggression. If your cat is terrified, they may defend themselves by acting aggressively.

Maternal Aggression 

When an animal or person approaches a mother cat and her kittens, maternal aggression can occur.

Even though they usually get along, the mother cat may growl or hiss, swat at, chase, or even bite another cat who gets too close.

After the kittens have been weaned from breastfeeding, maternal aggressiveness normally subsides.

Consider spaying a female cat who is maternally pushy to avoid more litters.

Play Aggression

Rough play is common in feline play since all feline play is based on pretend aggressiveness.

During play, cats may pursue, chase, swipe, sneak, pounce, kick, ambush, scratch, or bite each other.

Play might lead to overstimulation, which can lead to violence. This is a regular occurrence between cats of different ages.

Territorial Aggression 

Cats are no exception when it comes to being territorial.

When a cat perceives that its territory is being invaded, it may hiss, swat, growl, stalk, and/or chase the “intruder” – whether it’s another cat or a human.

How To Stop My Cat From Hissing At My Other Cats?

To stop your cat from hissing at the others, separating them can help to calm them down. Keep your cats separated with a gate made for kids or pets. 

Tall Pet/Baby Gate

It has been found that this gate worked wonderfully for cats and children.

A wire mesh gate can be a great solution if you require a higher gate since your cat could leap. They won’t get through, and jumping over them is difficult. 

 The benefit of this division is that you can keep track of whether or not your cat is eating, how much water they’re drinking, and their potty habits.

This is significant because at least one of the cats’ unexpected changes in behavior could be because of a medical condition.

Change The Environment In Which Your Cat Lives

It doesn’t have to take a lot of time, effort, or money to provide your cat with engaging activities.

You can provide an enriching experience in their environment. Pheromones go a long way to keeping the kitties calm. 

If you live in an apartment or a tiny living space, however, you may not require numerous diffusers.

Your Cats Should Be Reintroduced

After a few days of this, you might be ready to reintroduce the cats to each other. You can always open the door between the cats and watch the meeting from there.

If they appear to be curious and at ease with each other, have them socialize without the barriers.

To have a little more control, you can take both cats into a room and holding or leashing the aggressive cat if they’re harness trained. 

It’s not all rainbows and sunshine, because cats don’t forget their animosity overnight, but it’s incredible they can eventually stay in the same room without hissing and attacking each other!


Great Pet Care: Cat Hissing: Everything You Need to Know

Excited Cats: Why Are My Cats Fighting All of a Sudden? 5 Reasons for this Behavior

Preventive Vet: Why My Cats Started Fighting: How to Get Cats to Like Each Other Again

WebMD: How to Manage Fighting and Aggression Between Cats