By Dr. Justine Lee
Dr. Justine Lee, DVM, DACVECC, DABT, is a double board-certified emergency critical care specialist and toxicologist who is passionate about all things animal and veterinary medicine!
Types of cat aggression
Keep in mind that there are several different “types” of aggression in cats, including the following below (in alphabetical order):
- Fear Aggression
- Inter-Cat Aggression
- Maternal Aggression
- Pain-Induced Aggression
- Petting-Induced Aggression
- Play Aggression
- Redirected Aggression
- Status-Induced Aggression
- Territorial Aggression
How you deal with an aggressive cat will depend on what type of aggression your cat has.
Signs of an aggressive cat
First, let’s define what an aggressive cat looks like, because sometimes it can be confused with a fearful cat! It’s important to be aware of signs of aggression in cats, because the sooner you notice your cat’s body language of stress or aggression, the sooner you can break it up or intervene.
Signs of aggression in cats include:
- Ears pinned backward on the head
- Dilated pupils
- An arched back
- A fluffed tail held straight up
- Whiskers held out to the side
This looks similar to fearful cats, but note the differences with fear:
- Ears pinned back and held outward
- Dilated pupils
- Lying down with the tail tucked underneath or close to the body
- Whiskers flattened against the face
Now that you understand the body language of cats and know what to look for, please be aware there are several things you can do at home to deal with an aggressive cat.
How to deal with aggressive cat
Intervene early
The best way to avoid dealing with an aggressive cat is to prevent it. As a species, cats aren’t very adaptable. They hate any change to their environment and get easily stressed from it, which can lead to secondary behavioral—or even medical—problems. For that reason, if you’re thinking about adding cats to your household, ideally you want to get two kittens together from the same litter, as they are more likely to get along. If you don’t have a preference for male or female, consider getting two of the same sex, as they often get along better!
Not ready for two kittens? Adding a cat earlier than later is better, as younger cats are more likely to get along than when there’s a large disparity in age or time. If they aren’t littermates, consider a younger male and female, as they often get along better. Avoid the problem of having an aggressive cat to begin with by intervening early.
Make sure to introduce cats correctly
First impressions really matter to cats—you want the introduction to go slowly and go well. If you don’t introduce cats correctly, a lifetime of cat fighting or aggression can ensue, and it’ll be more challenging to get them to give the other cat a second chance. If for some reason you notice aggression between two particular cats, you should separate them and start all over again.
Slowly reintroduce them using positive reinforcement and barriers as needed. Start by setting up each of your cats in their own space. This should be behind closed doors where the other cat can’t go. Once or twice a day, rotate home base stations for an hour or two. Eventually, use a barrier to let them check each other out. When in doubt, go slow. Remember, first impressions are REALLY key for cats.
Use appropriate behavioral modification at home
I’m a big believer in positive reinforcement—like snacks, snacks, and more snacks. And we want the good stuff, like canned tuna, Temptations© treats, bonito flakes, and Churu© purees. This is stuff that you only whip out for special occasions—like making your cats get along! Keep in mind that we use these treats as a way of showing positive reinforcement: When cats sniff out the cat space without hissing, or have a calm, stress-free interaction, give them a treat immediately. If you wait too long (even 5 minutes later) it’s too far of a time gap and your cat won’t make the direct connection with calm behavior and a treat.
Veterinary professionals and veterinary behaviorists don’t advocate for negative reinforcement with cats (or dogs—please never use physical punishment). Not only can this make your cat avoid you altogether, but it can potentially make your cat’s behavior worse. The rare exception: For very young kittens, you can consider little snaps on the muzzle and scratching the belly when they are uncontrollable or showing signs of aggression. These are actions the mother or littermates would use to help socialize the rowdy kitten!
Lastly, consult a veterinary behaviorist
OK, you’ve tried it all. You’ve gone to your vet. Your cat is on drugs. And it’s still not working? It’s time for a pro: the veterinary behaviorist. This isn’t an online trainer—this is a veterinarian who has done an additional 2-3 years of advanced training in the form of a residency program. These are veterinarians who have the added letters DACVB behind their name, as this stands for a Diplomate of the American College of Veterinary Behavior. While veterinary behaviorists often work with animal trainers—and your veterinarian—these are the pros to go to with severe cases of cat aggression that aren’t responding to the above care. (You can also check out their recent book Decoding Your Cat for general training guidelines for cats too!).
