Why is my kitten's pupil smaller than the other? Should I worry?

Yes, unequal pupil sizes can indicate trauma or neurological disease. Schedule an exam with your veterinarian today or tomorrow at the latest. Monitor for ataxia (wobbly gait), weakness, lethargy or head tilting.

Thanks for using Petco Pet Education Center, formerly Petcoach! Good job noticing such a small change. This is only a reason of concern if it continues. Sometimes cats can have some minor trauma that may result in pupil constriction and will go away on its own. If this continues though and it is still present in a few days, I would recommend that you have Harry evaluated by a veterinarian for further assessment and treatment. Good luck and have a great day!

She is such a little cutie! Sometimes animals can be born with one eye smaller than the other. This condition is called microphthalmia. It can run in the genes and be passed from parents to the kittens, but it can also occur spontaneously. In most mild cases, they can lead a normal life and have good vision. Sometimes they can have problems with vision or cataracts down the road. At this time, I would recommend monitoring her. If you do see cloudiness, redness, squinting or discharge, then I would take her to a veterinarian for evaluation.

I suspect Alex has an infection. Kittens seem to be prone to both viral and bacterial eye infections and often require eye drops in order to heal. Additionally, if the infection gets bad enough, it can cause ulceration of the eye which is painful and can lead to the eye needing to be removed it not treated in a timely fashion. I recommend to call your veterinarian and have Alex seen today if possible. Hopefully it's just something that needs an eye drop! I hope this is helpful. Please feel free to post any additional questions!

Most of those flea/tick products are not labeled or recommended for kittens and can be toxic. Even some labeled for cats should not be used. I suggest you bathe her again with regular shampoo or baby shampoo to remove any of the other shampoo's residue from her. Rinse her eyes out with saline solution or just plain water. Those flea/tick shampoos can cause these types of side effects (unequal pupils and other neurological problems). The pupil will probably not go back to normal for a few days to a week. There is nothing else you can do at home.

Thank you for contacting Petco Pet Education Center, formerly Petcoach with your question about Bear. Oh no, poor girl. I'm quite worried about the breathing and unequal pupil size. The unequal pupil size is known as anisocoria, and it's a medical emergency when it happens suddenly. She really does need to see a vet now. Please take her into an ER vet clinic; if there isn't one in your area, there will be a vet on call for emergencies. The information to reach that vet is found on a clinic's answering machine or website. I hope this helps!

Thanks for using Petco Pet Education Center, formerly Petcoach! I would recommend he be evaluated by a veterinarian as soon as possible. Unequal sized in pupils can be due to either an underlying ocular or neurological issue, which should be seen by a veterinarian to determine which the possible cause is and any steps that need to be taken. Good luck!