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Why is my cat losing weight rapidly? Should I be concerned?

Updated On September 23rd, 2025

Pet's info: Cat | Domestic Shorthair | Male | neutered | 12.4 lbs

Joey has always been a big cat, has a long body and big back feet. He used to weigh about 18 pounds, but recently he lost weight pretty rapidly and with no explanation, now weighing just over 12 pounds. Should I be concerned? I know he was overweight before, but he looks so scrawny now compared to how he was.

2 Answers

Most Helpful Answer

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Answered By Dr. Melanie, BVSc MS

Veterinarian

Published on January 21st, 2018

Yes, I would definitely be concerned about Joey. Rapid weight loss can be a sign of a medical illness, and it's certainly not normal for a cat to lose this much weight so quickly without any changes in diet. Weight loss can be a very general sign of illness, and it could be caused by dental disease, systemic illness, infection, kidney disease, hyperthyroidism, diabetes inflammation, injury, or even cancer. I would take him into the vet first thing Monday for a physical exam, blood tests, and urinalysis. The vet can diagnose what has caused his rapid weight loss and how best to treat it. Good luck, I hope this helps!

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    Answered By Ana M, DVM

    Veterinarian

    Published on August 3rd, 2018

    Thank you for submitting your question regarding Kovu. I do believe he looks thin and 3 pounds is a significant amount of weight to loss in such a short time frame. He needs to see his veterinarian to determine the cause of his rapid weight loss. He could have intestinal parasites or an internal disease. He will likely require fecal testing and possibly blood and urine samples evaluated. In the meantime, continue to offer him plenty of food. I hope this information helps!

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    1Pet Parents found this answer helpful

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