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Why is my cat lethargic, itchy, and not eating after antibiotics?

Updated on September 23rd, 2025

Pet's info: Cat | Mixed Breed | Male | neutered | 13 years and 4 months old | 13 lbs

Hello, my cat is acting strange for the last couple of weeks. Nothing really changed, but he got very lethargic and depressed. First he got some itch - started licking and nibbling himself. The doctor suspected flees and prescribed revolution drops. He is still itchi and over the last couple of week become very passive. Took him to another doctor and he prescribed antibiotics. Doctor said his blood work is fine - see attached. he was eating fine, but with antibiotics his appetite decreased.

1 Answer

Most Helpful Answer

Answered By Daniel Fonza, DVM

Veterinarian

Published on January 6th, 2018

Hi there and thank you for using Petco Pet Education Center, formerly Petcoach to address your concern. I would agree with the veterinarian that the blood work does not look concerning at this time. If his appetite has decreased with antibiotics, I would recommend discontinuing the antibiotics and seeing how his appetite improves. If he continues to be inappetant or is lethargic, I would have the veterinarian recheck him to ensure everything is ok. If he continues to be itchy, I would recommend using a topical shampoo such as Douxo PS shampoo which can be found online quite easily and bathe twice weekly until resolved. I would also recommend using Essential 6 spot on by Dermoscent, which can also be found online. If he continues to be itchy, it may be time to consider switching to a different food or even consider seeing a veterinary dermatologist. I hope this helps! Please let me know if you have any other questions or concerns and I would be more than happy to help you further!

1Pet Parents found this answer helpful

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