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Why is my senior cat lethargic & scratching after Revolution?

Updated On September 23rd, 2025

Pet's info: Cat | American Shorthair | Male | neutered | 15 years and 6 months old | 9.5 lbs

My cat will be 16. He’s very anxious when we go out so I don’t like to take him to the vet when unnecessary, but he’s worrying me. He had fleas I couldn’t get rid of and was given revolution. He doesn’t have fleas anymore, but now he’s lethargic, overgrooming, and scratching himself until he bleeds. Any suggestions?

1 Answer

Most Helpful Answer

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Answered By Dr. Davis

Veterinarian

Published on March 12th, 2018

Some cats do get a skin irritation from Revolution. I’m glad the fleas are gone, Revolution is very effective that way. I would wash the application area with a warm damp cloth to remove any Revolution that is still on the skin. If he can’t reach the area to lick you can use a thin film of hydrocortisone cream on the sore to stop the itching. If he’s itchy all over a cool bath with a hypoallergenic shampoo may soothe the skin. If he continues to be lethargic and overgrooming then your veterinary should do and exam to make sure it’s just a skin reaction and they can then give an anti inflammatory injection which should make him more comfortable. Thanks for using Petco Pet Education Center, formerly Petcoach to help you care for Mio.

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