January 19, 2021 By Taylor Froiland, PharmD 0

Cat Eye Ulcers: How You Can Help Your Furry Friend

Although cats appear to have different looking eyes than ourselves, they are actually very similar in their structure. Like us, cats have an iris, a sclera, a pupil, and a cornea. The cornea plays an important role in your cat’s vision because it is what forms a cover over both the iris and the pupil and admits light into the inside of their eye, without which seeing would not be possible.

Round in shape and transparent in color, your cat’s cornea is kept moist and healthy on its outside surface by tears and on its inside by aqueous humor, the fluid that fills the anterior chamber of the eye. In addition to focusing and controlling the amount of light that enters your cat’s eye, the cornea also helps protect their eyes from dust, germs, and other, potentially dangerous, external substances.  

Its role as eye protector puts it more at risk than any other part of the eye for things like scratches, ingrown eyelashes, heat or smoke irritation, viruses, bacteria, and being affected by decreased tear production. Additionally, the cornea is also at risk for corneal ulcers.

What Are Cat Eye Ulcers?

A cat corneal ulcer is a penetration or erosion through the various layers of the cornea. There are three layers within the cornea made up of highly specialized skin cells that perform specific jobs. The epithelium is the outermost layer and is very thin, the stroma is the middle layer and the main supportive structure of the cornea, and the deepest layer is called the Descemet’s membrane.

A cat eye ulcer is an erosion or penetration that goes all the way down through the top two or three of these layers, from the epithelium to the stroma or epithelium to Descemet’s membrane. If the ulcer only reaches the stroma, fluid will be absorbed from your cat’s tears in the stroma, giving their eye a cloudy appearance. If the ulcer reaches all the way down to the Descemet’s membrane, then that is a very serious eye condition. If that membrane ruptures, the liquid inside your cat’s eye will leak out, causing the eye to collapse and leading to irreparable damage.

Causes of Cat Eye Ulcers

There are many different causes of cat eye ulcers, but the most common one is blunt or penetrating trauma. If your cat rubs their eye against a rough surface or gets a scratch on their eye from a thorn or another animal’s claw, it can lead to a corneal ulcer. Wounds that lead to ulcers could also be caused by a foreign object under the eyelid.

Additional causes of cat eye ulcers include the following:

·       Disease

·       Tear deficiency

·       Infection

·       Cannot close the eyelids completely

·       Paralysis of facial nerve

·       Foreign body

·       Burns from a chemical substance  

Symptoms of Corneal Ulcers in Cats

If you don’t realize that your cat has experienced trauma or received an eye wound, then you may not notice that they have a corneal ulcer right away. However, eye ulcers will cause your friend intense pain so you may start to notice them constantly pawing at or rubbing the affected eye on carpet or furniture. They may also feel the need to protect the eye, and so you might notice them squinting, blinking rapidly, or keeping their eyelids closed tightly.

Additionally, there are other possible symptoms of cat eye ulcers that often include one or multiple of the following:

·       Increased tearing

·       Colored discharge from the eye

·       A cloudiness in the eye

·       Redness of the eye

Like our own eyes, your cat’s eyes are extremely important to their survival and having a comfortable, enjoyable life. For that reason, if you notice anything out of the ordinary with them (even something seemingly small like excess rubbing), it’s important to contact their vet as soon as possible to have their eyes examined.

Diagnosis and Treatment of Corneal Ulcers in Cats

If you notice your cat showing any of the above symptoms and decide to bring them to the vet, make sure you explain to the vet everything you know about the situation. Tell them if your cat recently experienced any head trauma or fights with other animals, as well as all of the symptoms you noticed. Your veterinarian will perform a thorough physical examination of your cat and may use diagnostic dyes to help find corneal ulcers or erosions.

They may opt to test your cat’s eye fluid for any signs of bacteria or fungi that could be causing the symptoms or ulcer and, if they need to rule further things out, they may also order a blood test to check for any viruses.

Once it is determined that your cat has a corneal ulcer and the vet has figured out the specific cause, they will suggest the best treatment option depending on their condition. For example, if the ulcer is continuing to grow and get worse, a surgical operation may be necessary to keep it in check and repair it.

Most commonly, however, your vet will want to treat the underlying cause of the ulcer and then just let it heal. This can mean giving your cat antibiotics to treat or prevent bacterial infection, using an Elizabethan collar to prevent rubbing or scratching, giving your cat a topical ointment to increase tear production, and/or prescribing optical pain medications and anti-inflammatory drugs.


After they are diagnosed and treated for the ulcer, it’s important to limit your furry friend’s activity at home to give their eyes the best chance to heal and recover. Be sure to follow any information or direction your vet gives you and remember that you can fulfill all your cat’s medication needs conveniently online at ExpressVet.

We are here to help you and your cat through these difficult situations!