There are many reasons why cats may hiss, swat, chase, or fight other cats at home. Sometimes the cause of their aggression may start as something else, like pain or agitation unrelated to your other cat, but it can harm their relationship, leading to fear and stress that sticks around even when the original cause is gone. It’s important to act early if you notice signs of tension to prevent damage to their relationship.

To learn about different types of aggression and why your cat may be behaving a certain way, read our Aggressive Behaviour in Cats Guide.

Learn more about why conflict between cats may occur by reading our Intercat Tension Guide.

For a step-by-step guide on how to introduce new cats, or reintroduce cats who have been separated, read our Cat to Cat Introductions resource.

A common source of tension between cats is not having enough space of their own or feeling like they’re competing for resources like food and resting spots. Making changes to the environment can help your cats feel safer and reduce the amount of tension or fighting.

• Each cat should have their own resting space, litterbox, scratching posts, and food and water bowls that are far from others. This will help reduce tension that comes from sharing resources.
  • The minimum number of litterboxes you should have at home is the number of cats plus one. So, if you have two cats, you should have at least three litterboxes in different locations.
• Give your cats vertical space, like cat trees or shelves, and multiple places to rest in every room where the cats spend time.
• Prevent your cats from getting ambushed or cornered by giving them multiple escape routes away from areas where conflict happens. Hallways, doorways, food bowls, and litterboxes are common areas to see tension between cats. Use furniture, cat trees, or shelves to create new pathways for your cats to get off the ground and move around your house without feeling trapped.
  • If your cats ambush each other at the litterbox, add another litterbox in a different room of your house and separate any litterboxes that are side-by-side. Consider placing non-covered boxes in open areas, but beside a chair, shelf, or cat tree so the cat can see who’s coming and escape upwards if needed.

Our Cat Enrichment Guide provides an in-depth look at what you can give cats to keep them healthy and happy.

For information on setting up your cat’s ideal litterbox, read our Litterbox Guide.

Did you know cats can learn cues, like “sit” and “come”? Teaching your cat “come”, to touch your hand, or to go to their bed can be very helpful to get your cat to willingly move away from a situation when you notice signs of tension brewing, like staring or waiting to ambush.

Read our Reward-Based Training Guide to learn more about how to train your cat.

Our clicker training resource is a helpful tool for this as well – although it’s specific to dogs, it can also apply to cats.

Below are some additional resources we recommend for learning more about cat training:

• How To Stop Unwanted Cat Behavior With Clicker Training from Cat School
• How to Train Your Cat “Touch” or Finger Targeting Video
• Learn how to teach your cat to sit on a blanket or bed:
  • Teaching Go To Mat for Cats from CattleDog Publishing
  • Every Cat Should Learn This Skill (Mat Training) Video

Introducing a new cat should be done slowly and patiently, with the least comfortable cat setting the pace. We recommend using positive reinforcement, reward-based training to help cats feel more confident. Introductions are more likely to go smoothly if you have plans in place to make it a positive and safe experience for everyone.

Check out our Cat Introductions Guide for step-by-step instructions to introduce cats to each other.

Even cats who have lived together for a while may develop tension or conflict in their relationship. This may be because of stress, a change in the home, illness, a scary event, or something else that impacted them. Separating your cats and slowly reintroducing them to each other can be a way to give them the space and time they need to repair their relationship.

For information about aggression between cats, read our Aggressive Behaviour in Cats and Intercat Tension Guide. We also recommend reading this article about intercat tension by Cat Friendly Homes.

Your cat might feel stressed after being put in a carrier, traveling, and doing something scary, like seeing the vet. If you have only one cat, give them some time to settle in before trying to pet them or play with them after getting home.

If you have multiple cats at home you may notice they have fights after one comes home from a vet appointment. This is because new, unfamiliar scents from the vet clinic or other animals have come home too, and this can make your cats feel anxious and they may have a hard time recognizing each other. You can help your cat feel safe and prevent fighting after vet visits by placing them in a quiet room away from other cats, scent swapping, and slowly reintroducing them to the other cats.

For tips on re-introducing cats after travel read our Traveling in a Car with Your Cat Guide and Cat to Cat Introductions.

Learn how to reduce stress when taking your cat to the vet in International Cat Care’s guide.

For more information about aggression between cats, explore our Aggressive Behaviour in Cats Guide and resource about intercat tension.

A sudden change in behaviour can be a sign of a health issue or pain. See here for how to recognize pain in cats.

A veterinarian can also provide recommendations for treatments if your cat is experiencing stress or anxiety that is causing their unacceptable elimination.

You can find a veterinary clinic in your area using the ABVMA Directory.