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Why does my adopted cat poop outside the box after deworming?

Updated On September 23rd, 2025

Pet's info: Cat | Mixed Breed | Female | spayed | 3.5 lbs

Hello, I just adopted a cat whom I already knew tended to poop outside her box. It started after she was dewormed and never stopped. She doesn't always do this but often. She also had a very sore rectum before I adopted her. This is worse than I was led to believe and I need to find a way to help her stop so I can keep her in the house. I understand diet didn't help. Please if you have any advice...

1 Answer

Most Helpful Answer

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Answered By Lauren Jones VMD

Veterinarian

Published on April 3rd, 2017

Pixie's litter box habits sound quite frustrating! Most cases of cats defecating outside of the litter box are due to behavioral causes. However, since Pixie had an irritated anus when you adopted her, she may have been having difficulty urinating in the litter box due to worms or anal gland issues. Make sure her vet has checked a stool sample for the presence of parasites and possibly performed a rectal exam to check her anal glands. Consider adding an extra litter box, changing the litter type, and adding or removing a litter box hood. Calming pheromone collars or diffusers (Feliway is one example) can be beneficial in some cases. If you have further questions or concerns, feel free to request a consultation and we can discuss this problem in more detail.

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