Two Easy Ways to Start Earning Rewards!
Become a member today!
Members-only pricing and offers, personalized care notifications, Vital Care points back on every purchase and more!
Already a member? Sign in
Become a credit card member today!
Earn 2X Pals Rewards points at Petco
when you use Petco Pay!
APPLY NOW
Learn More About Petco Pay Benefits

My cat is subdued and not eating after flea treatment. Is this normal?

Updated on September 23rd, 2025

Pet's info: Cat | Russian Blue | Male | neutered | 3 years and 4 months old

My cat, Jax, is an indoor cat but he goes out every couple of days supervised. He was behaving strangely last night (jumping & running out of the blue) and this morning I noticed he had some irritation on his head above his eyes. He was scratching a lot and jumping up on all the furniture like he didn’t want to walk on the floor. I got some flea treatment and applied it about 10 hours ago. Now he is very subdued, hasn’t eaten and won’t come down from the shelf. Is this a symptom of fleas?

1 Answer

Most Helpful Answer

Answered By David Elbeze, DVM, MRCVS

Veterinarian

Published on February 21st, 2018

It's not likely to be a symptom of the fleas but it could be a symptom of the flea treatment you use, some of them can cause a side effect of lethargy and lack of appetite which usually does not last more than 24 hours. if by tomorrow Jax is not better, i would recommend taking him to your vet to get checked and treated.

1Pet Parents found this answer helpful

Smart Picks for Smart Questions

Related Questions

Is my kitten lethargic and shaking after flea treatment normal?

This is probably unrelated to the flea treatment, it could be an infection that Bobby is suffering from. If by tomorrow the symptoms do not improve I strongly recommend taking him back to the vet to get treated.

Updated on September 23rd, 2025

Health & Wellness

Why is my new kitten not eating and sleeping after flea treatment?

This isn't good. While a bath is stressful, it shouldn't stress him out so much that he hasn't eaten for 24 hours and slept the whole time. It's actually very serious when a cat won't eat, so I would take him into a vet immediately to get checked out.

Updated on September 23rd, 2025

Why is my cat so tired and sleeping a lot after flea medicine?

Depending on the extent of flea infestation, lethargy is not at all uncommon. Flea bites can drain a significant amount of blood and nutrients from the body, so when a severe attack as occurred, what you are describing is very much expected. If the exposure was not significant, it is possible that Milo may just be having a reaction to the medication itself. If this is the case, he should come out of it relatively soon. If not, I would have him reassessed by your veterinarian that prescribed the drug. Hope this helps.

Updated on September 23rd, 2025

Health & Wellness

My cat is still scratching after flea treatment. Is this normal?

If they were scratching due to fleas then it is not unusual they are still itching. The bites from the fleas will not go away overnight (imagine if you had mosquito bites, these persist for quite a time after the bite occurs) and often the die off of fleas will cause increased itching for a day or two. If the itching is severe your vet may prescribe medication to help, or if they are still itching excessively in a few days, seek veterinary care.

Updated on September 23rd, 2025

Health & Wellness

My cat is lethargic after flea/tick medicine. Is this normal?

Hello, thank you for using Petco Pet Education Center, formerly Petcoach. Great question! I would consider the lethargy you are describing as a common reaction but I would not say it is "normal". I think you should switch to a different product as the active ingredient in whatever you are using doesn't seem to agree with Shadow. It is better to switch because sometimes the lethargy can progress to a worse type of reaction with each application. Hope this helps. Best wishes.

Updated on September 23rd, 2025

My cat is tired and inactive after fleas. Should I go back to the vet?

I would start by treating the fleas. Fleas can be extremely aggravating and cause some pets to have weird changes in behavior. With large infestations of fleas, they can also cause anemia, which can cause profound lethargy. Other causes of lethargy can range from internal medical illness (diabetes, kidney disease, liver disease), infection, pain from arthritis, etc. I would recommend that you have Blu rechecked by her vet to look into these possible causes. The vet may recommend bloodwork to see how things are going inside of her body.

Updated on September 23rd, 2025

Health & Wellness

Why is my cat acting strange after Advantage flea treatment?

I wouldn't have a concern about Advantage for felines, especially if Cheeto has had it before. Sometimes the feeling of the medication on their skin can feel weird, and we apply it in an area so that they can't easily groom it off, which could cause some anxiety. Keep an eye on Cheeto and if he isn't back to normal in a day or two, have him examined by your vet.

Updated on September 23rd, 2025

Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Share