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.
- Treatment of feline herpesvirus-1 associated disease in cats with famciclovir and related drugs.
Journal of feline medicine and surgery · 2009 · Australia
Feline herpesvirus 1 (FHV-1) is a common virus that can cause eye and respiratory problems in cats, as well as skin issues. In a study, ten cats with symptoms related to FHV-1 were treated with an oral medication called famciclovir. The cats showed improvement in their conditions, including eye comfort and skin lesions, and the treatment was generally well-tolerated. Notably, f
- Ocular Manifestations of Feline Herpesvirus
Journal of Feline Medicine and Surgery · 2001 · United States
Feline herpesvirus-1 (FHV-1) is a common virus that affects cats all over the world, often leading to eye problems. The main eye issues caused by this virus include inflammation of the outer layer of the eye (conjunctivitis) and inflammation of the cornea (keratitis). The paper talks about how the virus causes these problems, how veterinarians can diagnose them using different
- Bilateral proliferative keratitis in a Domestic Long-haired cat.
Veterinary ophthalmology · 2002 · United States
A 9-year-old female spayed Domestic Long-haired cat was brought in because she had developed pink-white cloudy areas on both her eyes that were getting worse. The first vet thought she had an eye infection caused by feline herpesvirus-1 (FHV-1), but tests for the virus weren't done, and treatment with antibiotics and antiviral medications didn't help. Further tests showed some
- Feline herpesvirus-1: ocular manifestations, diagnosis and treatment options.
Journal of feline medicine and surgery · 2011 · United Kingdom
Feline herpesvirus-1 (FHV-1) is a common virus that affects cats and can cause serious eye problems. Once a cat is exposed to this virus, it usually stays in their system for life, and many will experience flare-ups of eye issues like redness, painful ulcers, and inflammation. Young cats are particularly vulnerable, and about half of those infected may have recurring eye proble
- Aetiology of corneal ulcers assume FHV-1 unless proven otherwise.
Journal of feline medicine and surgery · 2010 · United Kingdom
Feline ulcerative keratitis, which is a type of eye problem in cats that involves painful sores on the cornea, is often linked to an infection with feline herpesvirus 1 (FHV-1). This means that if your cat has a corneal ulcer, it's usually safe to assume that FHV-1 is the cause unless tests show otherwise. Other reasons for these ulcers can include injuries, issues with the eye
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.