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Why is my spayed cat suddenly aggressive and attacking me again?

Updated On September 23rd, 2025

Pet's info: Cat | British Shorthair | Female

My indoor cat was randomly attacking me and other people for no reason at all, one minute she was friendly then she attacked and went back to being friendly again. We went to consult a vet and they advised on getting her spayed, she was spayed couple months ago and she didn't attack or got aggressive towards anyone until couple weeks ago she attacked me. I don't understand what's going on. Help?

4 Answers

Most Helpful Answer

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Answered By Daniel Fonza, DVM

Veterinarian

Published on April 21st, 2018

It sounds as though Sam has a behavioral problem with aggression. If you have not tried the Feliway products yet, I would recommend doing so. These are pheremone products that are supposed to help calm cats down. I would make sure that she has plenty of environmental enrichment (toys, scratch posts, etc.). If these do not help, I would recommend discussing anti-anxiety medications with your veterinarian. I hope this helps! Please let me know if you have any other questions or concerns and I would be more than happy to help you further.

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Other Answers

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    Answered By Dr. Melanie, BVSc MS

    Veterinarian

    Published on December 12th, 2016

    There could be a couple of reasons behind this behavior. Marni could be painful from the spay surgery, and it is causing her to lash out with aggression. If she doesn't have any pain medications, you can discuss with the vet prescribing some safe pain medications for her. If she was in heat when she was spayed, then there could be lingering hormones in body still from it, leading to territorial behavior such as aggression. Finally, if there are other animals in your house, it could be that reintroducing her into the house after an absence she is lashing out to regain her dominant status in the home.

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    Answered By Makenzie Kurth, DVM

    Veterinarian

    Published on March 25th, 2018

    I’m so sorry to hear about Trooper. My first thought is pain. A painful cat will act completely out of character to prevent herself from getting hurt even more. Even though most cats are recovered by now, every individual is different and slaying as an older cat is potentially more painful than doing it as a kitten. If you are out of pain medication (or never got any), it’s time to call the vet to get some more. Consider other things to reduce stress for all the kitties such as pheromone therapy (see link below), an extra litter box or two, and providing plenty of toys and high places to hide/climb to. https://www.petco.com/shop/en/petcostore/product/comfort-zone-calming-diffuser-kit-for-cat If none of these are helping, see your vet to discuss other possibilities. Best of luck to you and your kitties!

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    Answered By Jeffrey Milner

    Veterinarian

    Published on September 26th, 2018

    It is not uncommon for there to be some behavioral changes when an animal is sterilized. In multi-animal households, the hierarchy can even change in some instances. Since this is all very new, I would give it at least another week or two before reading into anything too much. For all we know Mia is still experiencing some discomfort from her surgical procedure and may be cranky as a result. You may consider separating the two cats, if possible, for the next few days just to allow a little more time to elapse.

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