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My 11-year-old cat is suddenly vicious. Is it related to grief?

Updated On September 23rd, 2025

Pet's info: Cat | Domestic Shorthair | Male | neutered | 6 lbs

11yr old house cat normally loving and affectionate has become very vicious hissing, yowling and scratching. Hoped it was perhaps a neighvourhood cat scent on my recycle bag when i brought it inside but ive cleand that and my whole house but he is still in attack mode. I lost my other cat 2 months ago so i dont know if his behaviour could be related

1 Answer

Most Helpful Answer

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Answered By Jacqueline Nobles, DVM, DACVECC

Veterinarian, Board-Certified Emergency/Critical Care Specialist

Published on May 11th, 2018

Hello, Sudden changes in behavior can be secondary to an overactive thyroid or disease in the brain. I would advise you to have Digit examined by a veterinarian and discuss diagnostics such as bloodwork including thyroid levels, chest x-rays and abdominal ultrasound.

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