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Predicting the Unpredictable: Impulse Control Aggression in Cats

Learn the ins and outs of impulse control aggression in cats.

Put on Your Scuba Gear

I’m going to warn you, we’re diving into some deep stuff here. Impulse control aggression is a very serious condition where the brain develops differently, often times from neglect and abuse. This causes aggression, seemingly without warning … or so I initially thought …

Tuxedo cat in red collar
Miss Lucy is a gorgeous kitty with the silkiest fur.

This post is complicated, but it’s the best way to do justice for cats with impulse control aggression, like Miss Lucy. Their brains interpret stimuli very differently than the average cat brain, and constantly causes them to question every sound and move you make. Lucy has a pretty severe case of impulse control aggression, but over the few years, I’ve worked with her and she’s made progress. Likely, she’ll never be cuddly – these cats rarely are – but I believe it’s our job, to help these animals live lives that are full of love. Just because they don’t want constant snuggling and touching, doesn’t mean they don’t have the right to feel safe. I hope you find this informative.

Something Is Off with This Cat

From the day I piked up Miss Lucy, I knew something was off. I could barely touch her, and it wasn’t because she was feral: She was fearful. I figured as she got to know me, it would improve, and it did, but each step forward was increasingly discouraging, because those steps were so small. And then, some days, she’d take 10 steps back.

I knew her history included neglect and possibly abuse. She was surrendered to the shelter with one of the worst cases of FAD the shelter had seen in recent years; she had raw skin and open sores all over her body). And it’s true that cats with severe skin conditions are never quite the same. They often have hot, tender spots on their body. When touched, it triggers the cat to react.

There was thick scabbing above Lucy’s eyes from severe flea allergy dermatitis (FAD).

That was part of it, but that wasn’t all that was wrong.

Even when she happy, she would quickly turn. It’s like something in her brain says, “Wait a minute! Don’t trust this!” and there would be a hiss, bite, swat or growl.

A behaviorist diagnosed Lucy with impulse control aggression. But what is it and what did it mean for her future? I’m going to break down what I’ve learned from researching (although there isn’t a lot written on the topic), as well as lessons Lucy has taught me. She has been the #1 teacher, and I know I have a better understanding and can better help other cats with this frustrating but tolerable mental condition.

Impulse Control Aggression

Another name for impulse control aggression is status-induced aggression. It’s basically an animal’s need to control people and other animals so it feels safe.


Animals (and people) that are victims of neglect and abuse must make very quick decisions to keep themselves safe. The hypothalamus is used so frequently, it basically develops differently, and these cats feel overstimulated VERY easily (even by small things). In a way, the hypothalamus works too well. Fight and flight responses are extremely frequent.

Tuxedo cat at acupuncture
You can’t see it but Lucy’s head and back are covered in needles. She loves acupuncture.

REMINDER: Do not touch a cat in fight or flight. The risk of injury is high and they don’t recognitze you. Walk away and let the cat cool down for a period of time.

Mixed Messages

Every time Lucy is touched, hears a noise, smells something, feels something – the hypothalamus is stimulated. It also causes her to question EVERYTHING out of her control. She appears happy, then it’s like a switch flips (because in her brain, it does). Lucy may rub against you and hiss at the air. It doesn’t mean she doesn’t want to rub against you, she does. But her brain signals her to react to maintain control.

I know if I’m interacting with her and change anything, she will react. I can have her on my lap and pet her head. If I breath too deeply … move my hand a slightly different way … use a different finger … she will react. Sometimes, she’s completely relaxed and calm, as I pet her nose with one finger. Her eyes close, she’s quiet, then there’s a slight twitch in her body, and I know her brain just turned on to say, “Wait! Protect yourself.” And a growl, hiss, swat, or warning bite is about to follow. You can see why this is frustrating for me and her.

The brain is so different, it even interprets stimulation differently than a cat with a “normal” brain. One night, I was petting Lucy while she slept. When I reached the center vertebrae, her hips and base of her tail twitched. She was sleeping, so this wasn’t a conscious response. Immediately, I filmed it and sent it to her behaviorist. It’s very subtle in this video – watch for movements in her back half.

Turns out, that vertebrae creates a response in most cats, but it’s a different response, with different physical display. Usually, a cat’s back will have a sort of wave go through its spine, and it will push up into your hand for a good pet. But in cats with impulse control aggression, the brain interprets the stimulation differently, and causes the back half to twitch.

Lucy & Her Gab

Lucy’s won’t change. Maturity occurs around 2-3 years, so the brain is what it is. I do still work with her, using positive reinforcement to help combat her nearly constant anxiety, and Lucy needs medicine to help with her anxiety and pain. Her progress has been possible because of medication, specifically Gabapentin for pain and anxiety.

Medication is not the entire answer, but, it helps Lucy go from a 9 to 6, and sometimes even a 4. That is how bad some of these animals feel. Their brains constantly race and they’re pulled in every direction. They feel all physical contact more intensely than an “average” animal. The same with pain. Remember, Lucy had FAD, a serious skin condition, which left her with sensitive spots and nerve damage. The Gabapentin is a MUST to keep any pain and discomfort at bay, as well as relax her.

Drugs classified as SSRIs (often prescribed to help anxiety and depression in people), are an option for animals with impulse control aggression. Unfortunately, they don’t work for Lucy. Both Prozac and Paxil gave her serotonin syndrome (racing heart, dilated eyes). The good news: She told me she didn’t like SSRIs. She attacked the pill shooter if the SSRI pill was in it, but not with a Gabapentin capsule. She never fights the shooter when it’s holding Gabapentin and always swallows it without a fight, so I feel 100% okay with giving it to her.


I also do more holistic options which help in tandem with Lucy’s meds. A combo of treatments is crucial because keeping anxiety low helps Lucy feel more comfortable. It also helps keep people around her, and me, safe. One 30-minute acupuncture session every 5-6 weeks helps with anxiety, stress, pain, and digestive issues.

Learning Doesn’t Stop, for Either of Us

She still learn things, which is fabulous, including walking/running on the cat wheel and doing simple tricks for treats. Since she plays and kneads, I know she learned how to play as a kitten (which is good). The kneading is a sign of nursing, so she had a mom who loved and cared for her. These two facts help SIGNIFICANTLY.

When I started down this road with Lucy, I had no idea this condition existed. I thought these types of situations were strictly behavioral. I didn’t know their brains literally develop differently. I’ve learned so much, and I hope I someday meet another cat with this condition, because I feel more equip to help them.

They are projects – there’s no question. But they deserve love and understanding. And even with her predictable unpredictability, Lucy wins over ever person she meets. You can tell she isn’t a mean cat, just a slightly confused one.

Tuxedo cat on cat wheel
Lucy loves to run on her wheel.

By LizsKittyBootCamp

Hi, I'm Liz, and I'm a cat behaviorist who provides advice and insights on cat behavior.

7 replies on “Predicting the Unpredictable: Impulse Control Aggression in Cats”

I think my 3 yr old neutered male, Robinson, has this. I’ve read w/ interest your article on gabapentin, too, as a tool to manage this.
I got him when he 3 months old, he was runty and a bit sickly but I have no idea if he was abused. I’ve loved and spoiled him and things have been fine except about 2 years ago he reacted fiercely when he smelled his own ear on my finger–he went feral basically, chased me around the house hissing, screaming, and carrying on. Overnight he was ok and it didn’t happen again for over 2 years.

Fast forward to 7/2/21 (just a few weeks ago) and I was cleaning up some hairballs, he came to see, and omg, once again he became a vicious, screaming, hissing, hateful, feral monster. I was able to herd him into a spare bedroom but only after he shit on the kitchen floor (anal gland dump I think, and hissing and screaming while he did it). The stress of these attacks is beyond words (for me, and him too I”m sure). Overnight again mostly cured it, although he was a bit stealthy in the a.m, he got over it and was his usual playful friendly self for a bit…

But, that lasted less than 2 weeks. The next episode happened while I was on the phone and he was playing w/ my fingers. Out of apparently nowhere, from gentle and playful, his pupils dilated, he jumped away from me and started hissing and screaming. Sigh…once again a scared panicked nervous wreck (me and him both), I managed to get him into the attached garage. Oh the yowling, screaming, shrieking he was doing!! I feared the neighbors would think I was torturing him..But I was several feet away as he hissed and yowled and stared at me before he ran into the garage. Wracking my brain I simply cannot figure out what triggered him that time, which is key as to why I think he has this impulse control aggression.

Overnight again. I had gabapentin left over because he used to need it for vet’s visits (although the last few times, he didn’t). I put about 1/3 of the capsule (so probably around 30 mg or so) into his food in the am. This time he was mostly back to normal for only about 1 1/2 days before out of the blue I got “the stare”…my heart froze, I managed to shepherd him out the front door before that one turned into a full fledged fit. That one happened while he was lying under a table, he had been ok that day, but I came downstairs and when he saw me some switch flipped and he started staring…stalking…luckily I got him out fast that time.

I kept him outside and in the garage for a day or so but today felt guilty( and I missed him!), so I let him in. Again I put about 30 mg of gaba in his food. He’s been pretty close to his normal self although not energetic..quiet, more calm, plays if I play w/ him…and, importantly, isn’t shaking his head and licking his lips like he usually does ALL the time. He has allergies (I had testing done) but he is not on HA food (he hates it, and I haven’t pursued trying to find one he will eat). He’s mostly been napping (yay..)

I should also mention he was on a depo-medrol injection (steroid) starting in May, which stays in their system for a month or more. He was sick while on that, miserable, although it did clear up the allergy symptoms. But at what price. Never again. He’s been off that long enough that I don’t think the aggression is due to it, but I have to ask the vet if it can cause a long-term symptom like this.

I have a call in to the vet’s office as I want him checked (blood, urine, etc) because I know gaba is a pain med as well as anxiety med and the fact that he’s not shaking his head or licking his lips while on it, might mean he has pain. Or, maybe those are anxiety symptoms? I don’t know..but I know the gaba helps tremendously.

I thought I was going to have to put down my beloved boy. I’ve been a mess trying to figure out what to do, esp when I had him banished from the house. Do you think it’s possible impulse control aggression can come on gradually like that and manifest now that a cat is 3? Like I said, I don’t know if he was abused as a kitten, it is possible but he has lived 3 years w/ me w/ no abuse or neglect.

I don’t want to drug him, but I cannot live in fear of attacks. If they cannot find a physical problem and fix it (w/out it costing $1000s), he is going to have to be drugged, though.

Hi Requin,

It’s hard to say if it’s impulse control or something else. There are other things than can cause this behavior. Seizures and brain tumors are just two things. Also, it’s hard to say without knowing what his mother was like … We don’t know if he got all the nutrition he needed as a kitten or when he was in utero. Those can also affect brain development.

What you’re describing sounds like there is def a spike in the brain causing an outburst of aggression. I would talk to your vet about upping the gaba, or even exploring an SSRI (like prozac). Gaba is nice bc it has minimal side effects. If it’s working, upping the dose may keep Robinson’s anxiety at a low level and prevent it from spiking, which is what we want.

So def talk to you vet and see what they say. You can always hire a cat behaviorist or even go to a vet neurologist if you want to explore this more. Those obviously come with an expense, but they are still options I wanted to mention.

Please stay safe and keep doing what you’re doing. Robinson is lucky to have you in his corner. For sure those outbursts are very draining for him, and he doesn’t have control over them. His brain is just telling him to act that way. Remember it’s not personal. Thanks for loving him regardless of his challenges❤️

Thanks so much for replying, Liz. I hadn’t seen the reply but just found it when I came here to read your article again, because I just had another episode w/ Robinson. I’m more and more convinced he has the impulse control aggression. I was just cleaning the kitchen floor when he came in the room, all staring eyes and stalking and started to hiss. Clearly triggered just like in your article by a seemingly innocent. I avoided a fit by sitting on the floor and talking very gently to him. He slowly calmed down and came over, I petted him and he purred and somewhat relaxed.

More and more he wants to hang out in the back seat of the car in the garage because it’s a safe haven w/ little stimuli. He’ll have normal playful fun periods then periods of anxiety and nervousness. His overall normal mode is “on full alert and anxious” which has gotten worse in the past month or so since this all started. He’s always been skittish but not this bad.

As mentioned in my other msg, I did have him on a small amount of gabapenin and it worked great but the vet would not agree to keeping him on it. She would not give me any more. Also, Robinson had a very bad day of stomach ache, vomiting and diarrhea from either withdrawl off the gabapentin or a small (tiny) dose of human gaba (same dose, so not sure why that would matter). So I thought maybe it doesn’t agree w/ him after all.

I don’t really want him on kitty prozac or amytriptaline (sp?) because he’s very sensitive to drugs (got very sick on a shot of depo-medrol). Something like that might help but at what cost to him physically.

Speaking of cost, I am not prepared, as mentioned previously, to spend hundreds/thousands of dollars on this problem. My vet is basically useless. She will not even call me herself, always gets the assistant to call. I think she thinks I”m overreacting to “normal” cat behavior or something! I don’t think she has even heard of impulse control aggression. (I’m going to print your article and show her, but I don’t think it will do any good). All she keeps saying is to try Feliway. I have some, but am hesitant to try it fearing it might make him worse (because if he thinks it’s another cat…??) I suppose I should at least try it. Did you try that for Lucy and if so, what effect?

I did try to get an appointment at a cat-only vet around here, but they would not take him as a new patient. I’ve tried most of the vets in this area having lived here all my life and none of them are very good, they’re all sort of country-ish vets. Very limited. You are the only one anywhere who’s got a cat doing the same sort of thing as my cat is doing. No one I speak to has ever heard of this and no one has any ideas. I think it’s very likely Robinson was abused as a kitten and maybe it’s taking this long for the trauma to show. I don’t know. It’s tiring and sad.

Thanks for reading (if you do) my long reply.

I’m so sorry to hear about all of this. Gabapentin doesn’t normal cause nausea, so I’d be inclined to think something else was going on.

There are def other things you can try. You can try Feliway or any of the pheromone diffusers. Many people have had success with them. I have not, but the Feliway spray helped Lucy a little. You can also try a supplement called Solliquin. Lucy used to be on it and if you search using the search bar at the top of my page, you’ll find an article I wrote on it.

I’ve also had success with Rescue Remedy, which you can get on Amazon. Just make sure you get the one for pets.

It sounds like you may want to find another vet who you can have more open conversations with. I think it’s important to have a vet who listens and respects you and in turn who you can trust also. I would also try to get video of the behavior to show any vet you work with.

Another name for impulse control aggression is status-induced aggression. Your vet may be more familiar with that terminology.

Robinson is so lucky to have you!

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