Hello everyone,

I’m reaching out because I’m really struggling right now and could use some advice.

A few months ago, I had a situation with my two indoor cats that I posted about back then. I had adopted a second cat from a shelter to join my existing cat (after my very first one had passed away). After a long and careful introduction, they got used to each other and lived together quite peacefully.

However, back then, there was a phase where things became a bit tense. The older cat (who was there first) suddenly started hissing at the younger one more than usual. Sometimes she would actively look for her just to have a stare-down, followed by hissing and growling, and then either run away or hide under the sofa. At the same time, there were still many completely normal moments — they would sit next to each other on the couch, eat side by side, or even wait together in front of my bedroom door. I also tried a Feliway diffuser at that time. There were no obvious changes in the environment (no new furniture, enough litter boxes, food and water, no recent vet visits, etc.).

After that phase, things improved again and everything had been going really well for quite a while — until now.

Current situation:

I honestly feel like crying. Up until recently, everything was completely fine. But on the night from Friday to Saturday, around 4 a.m., there was suddenly a loud scream, and the two of them were apparently in a serious fight in the living room — not playful, but loud and aggressive.

By the time I got there, both were already hiding under the sofa. I only noticed some urine on the floor. I separated them for a few hours, got a Feliway diffuser again, and tried to reintroduce them around midday. At first, they ignored each other, and the older one was very alert, constantly watching where the younger one was. Over time it seemed to calm down — only some light hissing, and later they were even lying together on the sofa again and sniffing each other.

But then, just a short while ago, while I was still asleep, it happened again: a loud scream, another fight. I rushed in, and again both were hiding under the sofa. This time there was urine again, and also a bit of feces in the hallway.

I’ve separated them again now.

The hardest part is that I can’t even tell who the aggressor is, because they stop immediately when I enter the room. I also don’t understand why it seems to happen early in the morning, and why they can act completely normal again in between.

I really don’t know what to do anymore and would be incredibly grateful for any advice.

Best regards.