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Cher, Feline Specialist
Category: Cat Veterinary
Satisfied Customers: 21422
Experience:  Feline Healthcare & Behavior Specialist 40+ years Experience
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After giving our 12 yr old female cat a dose of Revolution

Customer Question

After giving our 12 yr old female cat a dose of Revolution for the first time, she started walking like she was tipsy. That was Saturday night . She wasn't eating and sleeping a lot for a few days, but her appetite improved today. She still has some balance problems and we want to know if there's anything we can do to stop it. Thank you, Pat
JA: I'm sorry to hear that. Could be a lot of things that cause lethargy. The veterinarian will know how to help Pat. Is there anything else the veterinarian should be aware of about Pat?
Customer: No that's the main problem. Our vet really pushed Revolution on us and I'm hesitant to tell them what's occurred.
Submitted: 10 months ago.
Category: Cat Veterinary
Expert:  Cher replied 10 months ago.

Hi, I'm Cher. Welcome to JustAnswer.

I'm reviewing your question now and will post back with your reply, shortly.

Expert:  Cher replied 10 months ago.

Hello again, Pat.

I'm so sorry your kitty has you worried, with these symptoms she exhibited after giving her the dose of Revolution on Saturday night. Different cats may experience different reactions to flea treatments that contain various insecticides. Revolution contains 'selamectin', which is applied topically and then enters the bloodstream through the first layer of skin. Walking like she was tipsy and not eating and sleeping a greater amount than usual could have been a reaction to the Revolution, which can cause 'ataxia' (not being able to walk straight). However, this may be coincidental, but there is a condition which causes a disturbance to the vestibular system, that controls equilibrium and balance, called Vestibular Syndrome or Vestibular Disease, and she may have developed that. The vestibular apparatus is located in the inner ear, and very often, an ear infection is to blame. It causes dizziness and nausea, and that's why cats don't like to eat and don't like to walk, if they don't feel balanced.

I'm glad to hear her appetite improved today! If she still has balance problems, this might linger for a while longer. Here is more information about Vestibular Syndrome:


To help with the lack of balance, you can give her some dramamine (dimenhydrinate), like we use for human motion sickness. This might help her feel less dizzy and be able to walk more normally, however, a side effect of this medication is sleepiness. Here is more information about the medication, precautions and dosage:


Don't feel hesitant to report this possible reaction to the Revolution to your vet; s/he should know what happened with your cat and next time, you can try a different topical flea treatment with a different insecticide and see how she does. Individual cats have adverse reactions to certain medications/treatments, and your vet should definitely know this information.

It would also be a good idea to bring her in for an examination in person, and a routine blood test, plus a check of her ears, to make sure she doesn't have an infection and/or Vestibular Syndrome.

I hope all will be well with your furry girl and she continues to improve!

Please be so kind as to rate my answer with positive feedback, as that is the only way I receive recognition from the website for my assistance. Thank you very much!

Providing a positive rating will not end our conversation, should you need me for any follow-up. Simply click 'Reply to Expert' for clarification or additional information, if needed.

Warmest wishes,


Expert:  Cher replied 10 months ago.

Just a quick follow-up to see how everything is going with your kitty.

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