Keratitis in Cats

See your vet immediately if your cat has a painful, cloudy, red, or partly closed eye. Keratitis is inflammation of the cornea, the clear outer layer at the front of the eye. Because the cornea needs to stay smooth and transparent for normal vision, even mild inflammation can cause discomfort, light sensitivity, tearing, and visible changes in the eye. In cats, keratitis is not one single disease. It is a broad term that includes several patterns of corneal inflammation, including ulcerative keratitis, stromal keratitis, and eosinophilic keratitis.

Many feline cases are linked to feline herpesvirus-1, especially when signs come and go over time. Other cats develop keratitis after trauma, chronic irritation, poor tear film quality, or corneal sequestrum, which is a dark area of dead corneal tissue seen more often in some flat-faced breeds. Some forms are painful emergencies, while others are chronic inflammatory conditions that need long-term management. Early veterinary care matters because delayed treatment can lead to scarring, deeper ulcers, vision loss, or even loss of the eye.

Your vet will start with a careful eye exam and history. They will want to know when the signs started, whether one or both eyes are affected, if your cat has had upper respiratory signs or past eye flare-ups, and whether there may have been trauma. The first goal is to decide whether the cornea is ulcerated, infected, inflamed without ulceration, or affected by another eye problem that can look similar, such as uveitis or glaucoma.

Common tests include fluorescein stain to look for corneal ulcers or leaks, tear testing to assess tear production, and tonometry to measure eye pressure. In cats with suspected herpes-related disease, your vet may also look for dendritic ulcer patterns with special stains. If eosinophilic keratitis is suspected, corneal or conjunctival cells may be sampled and examined for eosinophils. These steps matter because some medications, especially topical steroids, can be helpful in certain nonulcerative cases but unsafe if an ulcer is present.

Feline herpesvirus-1 is one of the most important causes of keratitis in cats. It is strongly associated with ulcerative keratitis and is also linked to some chronic nonulcerative patterns, including stromal keratitis and many cases of eosinophilic keratitis. Herpesvirus can remain latent in the body and flare later, so some cats have recurring eye disease even after the first infection has passed. Trauma, such as a scratch from another cat or self-trauma from rubbing, can also damage the cornea and trigger ulcerative keratitis.

Other contributors include dry eye or poor tear film quality, chronic irritation, and corneal sequestrum. Flat-faced breeds such as Persians and Himalayans may be at higher risk for corneal surface problems because their eyes are more exposed. Eosinophilic keratitis is considered an immune-mediated inflammatory condition, though the exact cause is still not fully understood. Young cats can be affected, but keratitis can occur at any age. Cats in multi-cat settings may also have greater exposure to infectious triggers such as herpesvirus.

Not every case can be prevented, especially when feline herpesvirus is involved, but early attention to eye changes can reduce complications. Have your cat seen promptly for squinting, discharge, cloudiness, or face rubbing. Avoid using leftover eye medication unless your vet tells you to. Some products can worsen ulcers or delay healing. Keeping nails trimmed and reducing conflict in multi-cat homes may also lower the risk of scratches to the eye.

For cats with recurrent herpes-related eye disease, your vet may discuss long-term management strategies based on flare pattern and severity. Good general health, stress reduction, and regular veterinary visits can help support overall eye health. Flat-faced cats and cats with prior corneal disease may need closer monitoring because they are more prone to surface irritation and recurrence. If your cat has chronic eye disease, ask your vet what early warning signs should trigger a recheck.

The outlook depends on the cause, depth of corneal involvement, and how quickly treatment starts. Superficial ulcers and mild inflammatory cases often improve well with prompt care, while deeper ulcers, melting ulcers, and sequestra carry a higher risk of scarring or vision loss. Herpes-associated disease can recur throughout life, so some cats need repeated treatment during flare-ups rather than a one-time cure.

Eosinophilic keratitis often responds to treatment, but recurrence is common and long-term management may be needed. Recovery usually involves frequent medication at home and one or more rechecks so your vet can confirm the cornea is healing safely. Even when some scar tissue remains, many cats stay comfortable and keep useful vision. The best outcomes usually happen when painful eye signs are treated early and follow-up care is completed as directed.