Said It Here

Why is my pet aggressive after running away?

Pets often undergo drastic personality changes and act aggressively toward other animals or family members after escaping or getting lost. This unpredictable hostility causes them to break house rules, terrorize other household pets, and ignore training, leaving owners feeling helpless and overwhelmed.

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
    trying to train the cat
  2. 2
    cleaning multiple litter boxes twice a day
  3. 3
    providing toys, treats, and scratching posts
  4. 4
    Using food-based rewards to build positive associations
  5. 5
    Having the partner feed the puppy and avoid direct looking or engagement during the day
  6. 6
    Removing the dog from the couch when it reacts
  7. 7
    Taking the dog to a quiet, dark room to let it calm down
  8. 8
    Slowing down the routine and letting life be boring to reset stress levels

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.

r/cats1 person · September 2026

This story is about a troublesome cat I’d love to hear your advice or any stories similar to mine.source ↗

But after that, it was like he was a different cat. He started playing aggressively with the female cats, making them hiss and get upset then they’d make up, only for the cycle to repeat.source ↗

He also started using the shower stall as a litter box but only whenever I left the house.source ↗

He has started breaking all these rules, and I’ve just given up on trying to train him; I’m very upset and don’t know what to do.source ↗

Pauchell4 · r/cats · 20 upvotes
r/dogs1 person · September 2026

6 months puppy rescued 1 week ago hates my husband.source ↗

Puppy lost his mind and barked aggressively over and over.source ↗

I feel like since he gained his confidence in the house he has gotten more aggressive.source ↗

Outside_Tailor2288 · r/dogs · 8 upvotes

Where this came up

People with this problem also raised