Written by Dr. Hayley Grove
Astrid 1 yr old FS DLH cat.
Astrid was recently adopted from a shelter. Before Astrid was adopted, her right eye was surgically removed due to severe complications of herpes viral infection of the eye. When Astrid arrived at the shelter, she had conjunctivitis which progressed to a corneal ulceration, resulting in the corneal ulcer rupturing. When this happens, little can be done, and the vet had to remove her eye to make Astrid more comfortable.
Astrid’s family became understandably concerned when her “good” eye (the left eye) presented with an unusual appearance, which can be seen in the image of Astrid’s eye below.
Notice the strands that come from the center of the iris (the colored portion of the eye around the black pupil). Fortunately, this is a congenital condition called Persistent Pupillary Membranes. Congenital means that Astrid was born this way, and the condition is not painful or harmful to her, and her vision is in that eye is normal as well.
You can also see a slight haziness on the surface of the cornea; we’ve determined that with her history of herpes viral infection, and the corneal ulceration, this is likely a scar on the cornea where a previous ulcer healed.
What Causes Corneal Ulcers
Chronic exposure to stress can cause cats to develop a herpes viral infection. This is very common to shelter cats, but also any feline whose exposed to chronic stress from things that you may not even consider to be stressful events to cats. Some common examples can be moving, home renovations, adding or losing a pet etc. Rubbing or pawing at the eyes can also increase the risk of ulceration.
Often, this may present as conjunctivitis – meaning the (you will notice the pink tissue around the eye will appear more red and puffy and may cover the cornea if severe enough). You may also notice a discharge from the corners of the eyes, and it will usually be whitish to yellow/green, then can lead to ulceration in some cases, when left untreated.
While corneal ulcers are a very common condition (since all cats are exposed to herpes as young kittens), it can still be serious, as it was in Astrid’s case.
To diagnose we will stain the eye to rule out (or identify) any ulceration of the cornea. cases, Once a definitive diagnosis has been made, we’ll discuss various treatment options, which depend on the severity of the case.
Treatment Options for Corneal Ulcers
We are fortunate to have good treatment options if the condition is detected and treated early. Antibiotic ointments can help with secondary bacterial infection (this is very common with herpes viral infections). Oral antiviral medications are also very effective and can be given in pill form. I also like to use drops that help with the cornea heal faster (Remend).
Recently, studies have shown that feeding probiotics to kittens in shelters can help improve the outcome of herpes viral infections. Probiotics have been shown to help, and are a healthy way to support the immune system. Seventy percent of the immune system is actually contained in the gut (gut-associated lymphoid tissue), so we recommend probiotics to all dogs and cats, especially puppies and kittens. Probiotics have even been shown to be very important to mental and emotional well-being in humans.
If your cat is rubbing their face or pawing at their eyes, you can use an Elizabethan collar (commonly called an “E” Collar). Remember, we need to prevent accidental trauma to the cornea, so “the cone” is our friend!
If you have recently adopted a cat or moved or undergone some change in our cat’s routine, they are at risk of a herpes virus flare-up. Some cats are more susceptible than others, as with everything in life. Try to minimize stress (link to OSU indoor cat initiative and Feliway), and start a probiotic like fortiflora. (reference purina fortiflora study that was mentioned above).
How Can I tell if My Cat Has a Corneal Ulcer?
Remember that eyes need careful attention because problems can develop quickly and become very severe. Early detection and treatment will improve success rates and outcomes.
We suggest that pet parents watch for pawing the eyes, rubbing the face on floor/bedding, squinting, shying away from light, differences in pupil size/shape, and how the third eyelid looks.
Paying attention to colors will help you identify potential problems, here are some quick tips- Redness indicates inflammation and likely pain. Most commonly you will see the redness of the conjunctiva. Redness inside the eye can be due to several conditions like inflammation, (uveitis), glaucoma, trauma, or a bleeding condition.
Yellow or green discharge from the eyes is cause for concern and may indicate a bacterial infection. If ulceration of the cornea is also present, bacteria can inhibit the healing of the cornea, and in severe cases like Astrid’s, can cause the cornea to rupture or melt. I recommend wiping out discharge gently with a cotton ball (wet or dry). We use cotton balls because the material is soft and will not damage the eye.
The discharge contains enzymes that can damage the cornea (melting ulcer), so flushing out the eyes and wiping away discharge is just as important as using “the cone.
Blue can indicate corneal edema, and this should be evaluated by a veterinarian. It can be seen also with conditions like corneal ulcers.
White on the surface of the eye usually indicates scarring (and it may resolve with time), mineral deposition, or lipid deposition in the cornea.
White inside of the eye can indicate infection inside the eye or a cataract, so this needs to be taken seriously as well.
To help patients, our goal is to reduce pain and help the immune system fight the virus so ulceration is less likely, and we should always remember how important it is to reduce stress in cats to help avoid illness in the first place.