Said It Here

Why is my cat suddenly attacking my other cat?

Sudden hostility between previously peaceful cats is often triggered by unneutered hormonal behavior, sexual drive, or dominance assertion. This abrupt aggression causes the victim to recoil and back away, disrupting household harmony and leaving owners confused about how to stop the fighting.

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    Keeping the cats currently separated
  2. 2
    Separating the aggressive cat into an isolated room
  3. 3
    Conducting controlled meets across windows and glass doors
  4. 4
    Switching to gravity food dispensers to eliminate mealtime competition triggers
  5. 5
    Putting the aggressive cat in a timeout
  6. 6
    waiting until the male cat is 7-8 months old to neuter
  7. 7
    getting the male cat fixed to stop the behavior
  8. 8
    Separating the cats for a full day before reintroducing them
  9. 9
    Using a large plastic storage bin as a temporary second litter box
  10. 10
    Keeping the cats fully separated using a cat tent and rotating their roaming times
  11. 11
    Using a multi-cat pheromone diffuser
  12. 12
    Putting puppy pads down for the victim cat to use the bathroom in a secure bedroom
  13. 13
    Waiting for the unfamiliar clinic smells to fade over a few days
  14. 14
    Keeping an eye on them to ensure they do not physically fight while recovering from surgery

In their words

Unedited, most upvoted first, each linked to the thread it came from.

When we came home, the next morning Panda viciously attacked Ziggy and scratched his ear so badly that it caused a portion to now appear missing on his our rimsource ↗

It’s been almost a month and his behavior has not changed.source ↗

We are completely lost.source ↗

ATrainer22 · r/cats · 25 upvotes

The problem I am having is between Baloo and Cheddar. Out of the blue, Baloo has begun to suddendly be aggressive and hostile towards Cheddar, who, in return, recoils and backs away.source ↗

AnonymousTeaLeaf · r/cats · 7 upvotes

He’s not been neutered yet so i’m just curious if this is sexual behavior, asserting dominance, parental-ish or what lol.source ↗

TheHedgeNerd · r/cats · 7 upvotes

I separated the two with a paper towel roll (😭), they’re now taking turns in their carriers and sniffing out the living room for the “threat”.source ↗

Now I’m just worried.source ↗

Idk, any advice please??source ↗

dreamer0303 · r/cats · 7 upvotes

About two weeks ago in the middle of the night I woke up to all : under our kitchen table growling at each other and tails real puffed up so I separated all 3 of them for a full day and put them back together and they where fine.source ↗

Now for the past week it’s like once a day they’ll be playing or chasing each other around and they all start growling and puffing up at each other for no apparent reason.source ↗

I currently have them separated again and not too sure what more I can do.source ↗

Designer_Tune4986 · r/cats · 1 upvotes

since I brought her back home my older kitten (already fixed months ago) is hissing at her constantly and is refusing to interact with her. I can tell this is upsetting the younger one.source ↗

promotepeace_xo · r/cats · 1 upvotes

Where this came up

People with this problem also raised