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Is Flagyl making my cat lose appetite instead of helping?

Updated on September 23rd, 2025

Pet's info: Cat | Domestic Shorthair | Male | neutered | 19 years and 1 month old | 9.5 lbs

Hi! Tony was prescribed flagyl in a liquid form about 5 days ago because he was having diarrhea and didn’t want to eat for one day. the diarrhea has improved but his appetite has not been great and I was instructed to give the flagyl for 7 days. I also read that side effects can be diarrhea and loss of appetite. I guess I’m a little confused about these side effects since they are the reason I had to take him to the vet in the first place

2 Answers

Most Helpful Answer

Rodrigo Roca, DVM

Answered By Rodrigo Roca, DVM

Veterinarian

Published on February 23rd, 2019

Hello, thank you for your question about Tony.

Flagyl (metronidazole) is an anti-diarrheal medication that also has antibiotic/antiparasitic properties. The side effects that you found such as decreased appetite and diarrhea are usually associated with these properties. In general these side effects are less likely and the benefit of giving the Flagyl.

I would recommend continuing the Flagyl as directed. Additionally you could offer Tony a bland more palatable diet. Some options include a canned food diet that is designed for GI health. You could also try home cooking food such as boiled chicken/hamburger. If Tony's inappetance continues I would recommend having him rechecked by your veterinarian for further evaluation and diagnostic workup.

Hope this helps, good luck!
Vote Icon1Pet Parents found this answer helpful

Related Answers from Veterinarians

  • Answered By Ana M, DVM

    Veterinarian

    Published on February 24th, 2019

    Thank you for submitting your question regarding Tony. I suspect his appetite has changed more due to his recent gastrointestinal upset than to the antibiotics. Once he has finished the medication, wait a few days and try to mix in the kidney diet again. Hopefully he will transition back over to it without a struggle. I hope this information helps!

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    1Pet Parents found this answer helpful

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