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Dr. Michael Salkin
Dr. Michael Salkin, Veterinarian
Category: Cat Veterinary
Satisfied Customers: 30398
Experience:  University of California at Davis graduate veterinarian with 45 years of experience.
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Thank you for being able to help today. Snowy has had a

Customer Question

Good afternoon, thank you for being able to help today. Snowy has had a dialated pupil for approx 10days. Now that eye is normal and the other eye is dialated. He is 16yrs old. He has been coughing/sneezing for a couple days and pretty tired. He does not seem to be in pain. If these are symptoms of something painful then we need to know.
Submitted: 11 months ago.
Category: Cat Veterinary
Expert:  Dr. Michael Salkin replied 11 months ago.

You're speaking with Dr. Michael Salkin. Welcome to JustAnswer. I'm currently typing up my reply. Please be patient. This may take a few minutes.

Customer: replied 11 months ago.
Thank you.
Expert:  Dr. Michael Salkin replied 11 months ago.

I'm sorry that your question wasn't answered in a timely manner. Unequal sized pupils is called anisocoria and it has quite a few possible etiologies. The two most common causes are the leukemia (FeLV) virus and the spastic pupil syndrome - a condition unique to cats in which owners report anisocoria, which may sometimes be transient and independent of ambient light levels. Clinically, cats with this syndrome appear to be healthy, are visual, and have no ocular abnormalities beside unusual behavior of the pupils. Unfortunately, most affected cats test positive for FeLV at the initial presentation but not all which confounds the diagnosis. It's unclear to me how Snowy's coughing and sneezing might be related to anisocoria unless primary ocular inflammation is associated with his upper respiratory infection.

Anisocoria also results from primary iridal (iris) disease - an example of an inflammatory process causing miosis (an abnormally small pupil); and primary neurologic disorders involving cranial nerve III and Horner's syndrome. Retinal disease - hemorrhage and/or detachment needs to be considered as well. If the retina isn’t perceiving light or telling the brain that light has been perceived, the pupil will become mydriatic – larger than usual. Retinal disease is relatively common in hypertensive cats and so blood pressure assessment is important in these cats.

The initial database should involve testing for FeLV and a complete ophthalmic examination including menace response, dazzle, palpebral, pupillary light, and vestibulo-ocular reflexes. Fluoroscein staining of the cornea should be performed looking for corneal trauma and intraocular pressure should be measured (the elevated pressure of glaucoma will enlarge the pupil (mydriasis) and the lowered pressures of uveitis will make the pupil miotic).

Much of the above is beyond the capability of many generalist vets so Snowy's vet may recommend referral to a board certified veterinary ophthalmologist. Please see here:

Please respond with further questions or concerns if you wish.

Customer: replied 11 months ago.
Thank you from the information. Is any of this painful? He's holding his head cockeyed now. Gosh, this is always the case when it's a holiday weekend.
Expert:  Dr. Michael Salkin replied 11 months ago.

Potentially, yes. A head tilt is pathognomonic (specifically indicative) of vestibular (balance) disorders. I need to consider peripheral (involving the inner/middle ears), central (involving the cerebellum and/or brain stem), and idiopathic (most common) vestibular disorders. All of these disorders can result in anisocoria. I understand your logistical constraints. It seems to be a rule that our pets become ill on holidays, weekends, and when we're on vacation. Please continue our conversation if you wish.

Customer: replied 11 months ago.
Thank you. We will keep a close eye for the neXt few hours.
Expert:  Dr. Michael Salkin replied 11 months ago.

You're quite welcome. I can't set a follow-up in this venue so please return to our conversation - even after rating - with an update at your convenience. You can bookmark this page for ease of return.

Expert:  Dr. Michael Salkin replied 11 months ago.

I'm just following up on our conversation about your pet. How is everything going?

Dr. Michael Salkin