Eye Conditions of Cats and Dogs


Last month you learned that many common eye problems are quite manageable, despite the fact that you’ve been conditioned to believe everything affecting the eye is an emergency. Here are a few more issues you might encounter, including one or two that are really very serious.

Entropion is actually an eyelid condition. Lids with entropion are turned slightly inward. Some of the fur and eyelashes end up touching the clear part of the eye, causing ongoing damage to this delicate surface. Entropion needs to be fixed with plastic surgery. Don’t worry—that doesn’t mean you’ll be referred to a doctor who drives a little sports car.


Cataracts are a frequent topic of conversation in my exam room. Many older pets have cloudy, bluish-looking eyes that do not actually contain a cataract. We can tell the difference using our equipment at the clinic. Cataracts can be removed with surgery if they are causing a problem. They don’t seem to affect pets as much as they affect people, probably because most pets don’t drive at night or read the fine print in advertisements.
It’s really scary to see two different sizes of pupil (anisocoria) or eyeballs jerking from side to side (nystagmus). Don’t panic. Yes, it could be something serious, but it’s quite often something minor, like an ear infection or temporary case of vertigo. Yes, it could be a stroke, but strokes carry a very different set of implications for pets as compared to people. A human being should be rushed to the hospital because every minute counts, but your vet won’t have access to the same kind of super-aggressive stroke therapies. Most pets that have apparently had a stroke do very well afterwards.


A corneal ulcer is an open wound on the clear surface of the eye. These can be totally invisible, evidenced only by squinting and tearing in the damaged eye, or they can be big and cloudy with obvious sticky spots or bulges on the eye’s surface. Infected corneal ulcers might get deeper and deeper until the inside of the eye actually begins to leak, so these need a prompt visit to the vet.


One especially sinister eye condition is glaucoma, because it can develop without warning and result in overnight, permanent vision loss. Sadly, this serious disease is difficult to recognize without the special equipment we use at the clinic. Glaucoma eyes that are becoming blind get bloodshot and inflamed. They might have an unusually large pupil (which is the black area in the center of the eye). If left untreated, glaucoma can be very painful.
A cat with really large pupils could be in serious trouble with high blood pressure. This can quickly develop into permanent blindness. A cat with big black eyes should go straight to the vet.


For the most part, the eye is quite sturdy and resilient. There’s no need to besqueamish about getting a good look inside there before heading off to the vet for some testing. Your doctor will take it from there.

Dr. M.S. Regan