CATS · Condition guide
Corneal ulcers in cats: real veterinary cases
Eye problems in cats are common and frequently more serious than they look. The single most useful sign is squinting — cats hide pain remarkably well, and squinting one eye almost always means a painful ocular surface problem. The most common causes are corneal ulcers (often secondary to herpesvirus, scratches, or foreign bodies), corneal sequestra (a dark plaque unique to cats, common in Persians), and less commonly glaucoma.
Diagnosis hinges on a fluorescein stain — the green dye sticks to areas of corneal damage and is invisible elsewhere. Dendritic, branching ulcers are pathognomonic for herpesvirus reactivation. Treatment depends on cause: topical antibiotics for routine ulcers, antivirals (cidofovir or oral famciclovir) for herpesvirus, surgical referral for non-healing or deep ulcers. Glaucoma in cats is usually secondary to chronic uveitis and warrants a search for the underlying cause.
What vets typically check for
- Always start with fluorescein stain — sees ulcers invisible to the naked eye.
- Schirmer tear test if dry eye is suspected (uncommon in cats).
- Tonometry (intraocular pressure) — essential if pupils look abnormal or vision seems reduced.
- Topical antibiotic + analgesia for simple ulcers; antiviral therapy if dendritic.
- Refer to ophthalmologist for non-healing ulcers, deep stromal ulcers, or uveitis/glaucoma.
Not a replacement for veterinary care. Use this to walk into the conversation prepared, not to self-diagnose.
Real cases from the veterinary literature
Peer-reviewed reports our semantic search surfaces for Corneal ulcers and eye disease in cats. Click into any case for the full abstract — or run a personalised search with your pet's exact details.
- EXPRESS: Treatment rationales and outcomes for cats with lens luxation: 136 eyes (2007-2023).
Journal of feline medicine and surgery · 2026 · United States
A group of 115 cats with lens luxation (a condition where the lens of the eye is displaced) were treated using different methods, including surgery and medication. Many of the cats were not able to see when they were first examined. The most successful treatment was intracapsular lens extraction (ICLE), which helped 92% of the eyes regain vision and maintain normal eye pressure
- The Clinical Efficacy of a Topical Selective EP2 Receptor Agonist Against Feline Glaucoma That Is Not Responsive to Conventional Anti-Glaucoma Eyedrops.
Veterinary ophthalmology · 2026 · South Korea
A group of 11 cats with glaucoma that didn't respond to regular eye drops were treated with a new topical medication called Omidenepag isopropyl (OMDI). Before starting the treatment, the cats had high eye pressure, averaging 53.6 mmHg, and some had already lost their vision. After using OMDI, four cats maintained their vision long-term, while others showed short-term improveme
- Effects of Omidenepag Isopropyl Versus Latanoprost Eye Drops on Intraocular Pressure, Pupil Diameter, and Anterior Chamber Parameters in Normal Feline Eyes: A Pilot Study.
Veterinary ophthalmology · 2026 · South Korea
A group of 22 cats had their eye pressure measured after receiving either a new eye drop called omidenepag isopropyl (OMDI) or a common treatment called latanoprost. The cats treated with OMDI showed a significant drop in eye pressure without affecting pupil size, while those given latanoprost had a greater decrease in pupil size. Both treatments improved certain eye measuremen
- Reference Ranges of Intraocular Pressure, Central Corneal Thickness, and Ocular Surface Temperature in Van Cats.
Veterinary ophthalmology · 2026
A group of 307 healthy Van Cats had their eye pressure, corneal thickness, and eye temperature measured to establish normal ranges for these parameters. The study found that eye color and sex had minimal effects on these measurements, with blue-amber cats showing slightly higher eye pressure and corneal thickness than blue-blue cats. Overall, the measurements were consistent be
- Evaluation of topical ophthalmic application of penciclovir cream in cats with experimental ocular feline herpesvirus-1 infection.
American journal of veterinary research · 2026 · United States
A group of cats with eye problems caused by feline herpesvirus-1 (FHV-1) were treated with a topical cream called penciclovir to see if it would help. The cats received the cream three times a day for two weeks, and while there were no major differences in their eye symptoms compared to those given a placebo, the cats treated with penciclovir showed a quicker improvement after
- Feline Conjunctival Sequestra-A Case Series.
Veterinary ophthalmology · 2026 · Brazil
A 3-year-old male Persian cat was brought to the vet after experiencing two months of squinting and watery discharge from his right eye. Upon examination, the vet found a black plaque on the conjunctiva (the membrane covering the eye) and noted some inflammation. The cat had a similar issue with the cornea, which is the clear front part of the eye. Treatment details weren't spe
Frequently asked questions
- Can I use leftover eye drops from another cat?
- Never. Some antibiotics (gentamicin, neomycin) can melt the cornea in deep ulcers, and any drops containing steroids can be catastrophic if a herpesvirus ulcer is present. Always get a fresh diagnosis with fluorescein stain before treating any cat eye problem.
- Why do herpesvirus ulcers keep coming back?
- Feline herpesvirus type 1 establishes lifelong latency in the trigeminal nerve, then reactivates under stress (boarding, new pet, surgery, illness). Recurrent ulcers benefit from oral famciclovir during flare-ups and L-lysine supplementation (though evidence for lysine is mixed).
- When is an eye an emergency?
- Sudden squinting in an otherwise well cat, any visible cornea cloudiness or depression, a globe that looks larger than the other, or any eye injury — all warrant same-day veterinary attention. Eye disease can progress from manageable to vision-loss in 24-48 hours.