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Why is my cat losing weight after switching to adult cat food?

Updated On September 23rd, 2025

Pet's info: Cat | American Shorthair | Male | neutered | 1 year old | 11 lbs

Hello, my cat has lost around 3 pounds in 3-4 months and I gave him a tablet with praziquantel and pyrantil pamoate in case it is from worms. I haven’t noticed worms or fleas on him. He only goes outside for a few seconds at a time with me right by him and only a few times a month. He still eats but not as much as he used to. I recently switched him to adult food. Could that be the cause of his weight loss? If it is due to worms, when should he start gaining weight?

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1 Answer

Most Helpful Answer

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Answered By Andrea M. Brodie, DVM

Veterinarian

Published on August 7th, 2018

A 3 pound weight loss is indeed significant and not normal. There could be many reasons for this, and there is just no way to pinpoint the cause without a hands-on exam and possibly blood work. I suggest you take your kitty to a veterinarian for a wellness exam.

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