Petco Text Logo
Petco Pet Logo

My cats suddenly fight when left alone. How to stop cat aggression?

Updated On September 23rd, 2025

Pet's info: Cat | American Shorthair | Male | neutered | 4 years and 2 months old | 16 lbs

I have an 10yr old and 4yr old cat that have lived together for yrs w/o any problems. Recently the younger cat has started buying the older cat. They are not hostile 95% of the time, and the attacks only happen when they are left alone. We've noticed the older cat being injured about times in the last month's. Is there anything we can do to minimize the aggression?

1 Answer

Most Helpful Answer

Image profile

Answered By Amber W

Veterinarian, Certified Veterinary Acupuncturist

Published on June 30th, 2018

I'm sorry to hear you're having an issue with your two cats. The first step to take is to completely separate your cats when you are not home to keep everyone safe. It's also a good idea to have separate resources for all the cats in the household. So this means separate water and food bowls for each cat. Also, for a two cat household, 3 litter boxes are recommended. Finally a Feliway diffuser may help reduce tension in the household. A few tall cat towers can also help the cats to have their own private areas but you should only allow them together when they are directly supervised. Sometimes when one cat shows aggression toward another cat it can indicate a health issue in one or both of the cats. It would be a good idea to have both Onyx and your other examined by your veterinarian to rule out health issues. Thanks for using Petco Pet Education Center, formerly Petcoach and best of luck to you!

Vote icon

1Pet Parents found this answer helpful

image
Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Sponsored