Thu, Feb 8, 2024

I've just noticed one pupil bigger than the other.

Create an account to access Dr. Frank’s answer to this concern.

The vet's response to this question is only available to members of Dr.Tail Create a new account to access +100K cases in Dr.Tail.

  • 24/7 priority consultations
  • Analysis of the cause of the issue
  • Home treatments and care tips
  • Guidelines for vet visits
  • Vet experts matched to your needs
or continue with
Dr. Frank

When a cat presents with one pupil larger than the other, a condition known as anisocoria, it's important to assess the situation carefully as it can be indicative of various underlying health issues. Anisocoria can be caused by several factors including trauma, inflammation, neurological problems, or diseases affecting the eye itself.

Firstly, observe your cat's behavior. Is he showing any signs of pain, such as squinting or pawing at the affected eye? Is there any discharge, redness, or cloudiness in either eye? Also, note if there are any changes in his vision or if he's bumping into objects.

At home, you can perform a simple light test. In a dimly lit room, shine a light into each eye separately and observe the pupils' reactions. Normally, both pupils should constrict equally in response to light. If the pupils react differently, this is a sign that there may be an issue that needs professional attention.

If your cat is not currently on any medications and has no history of medical conditions, it's less likely that the anisocoria is due to a systemic issue, but it's not impossible. Since the condition has been present for a day and is ongoing, it's important to monitor for any additional symptoms that may arise.

In the absence of other symptoms, you may choose to monitor your cat closely at home for a short period. Ensure he is in a safe, comfortable environment where he cannot injure himself, especially if his vision may be compromised.

However, if you notice any of the following, it would be prudent to seek veterinary attention promptly:

1. Behavioral changes such as confusion, lethargy, or aggression.
2. Signs of pain like excessive meowing, restlessness, or hiding.
3. Any neurological symptoms, including difficulty walking, head tilting, or seizures.
4. Changes in the appearance of the eye(s), such as increased redness, cloudiness, or a visible third eyelid.
5. Any signs of trauma to the head or eye area.

Remember that eyes are delicate organs, and conditions affecting them can progress rapidly. It's better to err on the side of caution when it comes to eye health. A thorough examination by a veterinarian can help determine the cause of the anisocoria and whether it's an emergency situation. The vet may perform a complete physical exam, assess ocular health, and possibly recommend further diagnostic tests such as blood work or imaging.

In summary, while some cases of anisocoria can be benign and transient, others can signify serious health issues. Close monitoring at home is key, and if any additional concerning symptoms develop, immediate veterinary care is warranted.

If you have any additional questions, please don’t hesitate to come back to us! Thank you.