Corneal Ulcers in Cats: Causes, Treatment & Recovery

Quick Answer
  • See your vet immediately if your cat is squinting, holding one eye shut, or has a cloudy, painful eye. Corneal ulcers can worsen fast.
  • A corneal ulcer is a break in the clear front surface of the eye. In cats, common causes include feline herpesvirus-1, scratches, foreign material under the eyelid, and self-trauma from rubbing.
  • Most superficial ulcers heal in about 3-7 days with prompt treatment, but herpes-related or infected ulcers can take 1-3 weeks and may recur.
  • Treatment often includes a fluorescein stain test, antibiotic eye medication, pain control, an e-collar, and rechecks. Deep, melting, or perforated ulcers may need urgent specialist surgery.
  • Typical US cost range in 2026 is about $150-$450 for an uncomplicated visit and medical treatment, and roughly $1,000-$3,500+ if advanced procedures or ophthalmology referral are needed.
Estimated cost: $150–$3,500

What Is a Corneal Ulcer in Cats?

A corneal ulcer is an erosion or open sore on the cornea, the clear outer layer at the front of your cat's eye. Vets may also call this ulcerative keratitis. Because the cornea has many nerve endings, even a small ulcer can be very painful. Cats with ulcers often squint hard, tear excessively, and avoid bright light.

Some ulcers affect only the surface layer and heal quickly with medical care. Others extend deeper into the cornea, where they can become infected, soften or "melt," or even rupture. That is why a painful eye should never be treated as a wait-and-see problem.

In cats, corneal ulcers are especially important because feline herpesvirus-1 (FHV-1) is a common trigger. Trauma is also common, including scratches from another cat, plant material, or rubbing at an irritated eye. Early treatment gives your vet more options and improves the chance of comfort, healing, and vision preservation.

Symptoms of Corneal Ulcers in Cats

  • Squinting or keeping one eye tightly shut, often a sign of significant pain
  • Excessive tearing or watery discharge, sometimes with mucus
  • Redness of the white of the eye or swollen tissues around the eye
  • Pawing at the eye or rubbing the face on furniture or carpet
  • Cloudy, blue, or hazy appearance on the cornea
  • Light sensitivity and hiding in darker areas
  • A visible pit, dent, or dark spot on the eye surface, which can suggest a deeper ulcer
  • Yellow-green discharge, worsening pain, or sudden eye shape change, which can suggest infection or rupture risk

Corneal ulcers are painful and can become emergencies quickly. See your vet the same day if your cat is squinting, has a cloudy eye, or keeps rubbing at the face. Seek urgent care right away if the eye looks sunken, bulging, very cloudy, has thick discharge, or your cat suddenly cannot open it. Do not use leftover eye medication unless your vet says it is safe. Eye products containing corticosteroids can delay healing and may make some ulcers dramatically worse.

What Causes Corneal Ulcers in Cats?

Feline herpesvirus-1 (FHV-1) is one of the most common causes of corneal ulceration in cats. After the first infection, the virus can remain dormant and flare again during stress or illness. These flare-ups may cause recurrent eye pain, conjunctivitis, and ulcers that heal more slowly than a simple scratch.

Trauma is another major cause. Cats can injure the cornea during play or fights, from plant material, dust, grooming accidents, or from rubbing an already irritated eye. A foreign body trapped under the eyelid can keep scraping the cornea every time the cat blinks.

Other possible causes include bacterial infection, dry eye, eyelid or eyelash abnormalities, exposure to irritating chemicals, and chronic corneal disease. In some cats, a nonhealing ulcer points to an underlying problem that also needs attention, not only the ulcer itself.

How Are Corneal Ulcers Diagnosed?

The most important test is a fluorescein stain. Your vet places a special dye on the eye, and damaged corneal tissue takes up the stain. This helps confirm that an ulcer is present and can also help show its size and pattern. The test is quick and is a routine part of evaluating a painful eye.

Your vet will also examine the eyelids, tear film, and the rest of the eye to look for causes such as a scratch, foreign material, herpes-related disease, or eyelid abnormalities. If the ulcer is deep, chronic, infected, or not healing as expected, your vet may recommend additional testing such as tear testing, cytology, culture, or referral to a veterinary ophthalmologist.

Depth matters. A superficial ulcer may be managed medically by your primary care vet, while a deep or melting ulcer may need urgent specialty care to protect the eye from perforation.

Treatment Options for Corneal Ulcers in Cats

Spectrum of Care means you have options. Here are treatment tiers at different price points.

Conservative

$150–$450
Best for: Cats with a small, superficial ulcer, stable eye exam findings, and pet parents who can reliably give medication and return for rechecks.
  • Office exam and fluorescein stain
  • Topical broad-spectrum antibiotic to reduce secondary bacterial infection risk
  • Pain relief, often including oral pain medication and sometimes atropine if your vet feels it is appropriate
  • E-collar to prevent rubbing
  • Home nursing and a recheck in about 3-5 days
Expected outcome: Often very good when the ulcer is shallow and treated early. Many uncomplicated ulcers improve quickly and heal within several days.
Consider: This approach depends heavily on home care and follow-up. It may not be enough for herpes-related, infected, deep, or nonhealing ulcers. Frequent eye medication can be challenging in some cats.
Most Common

Standard

$350–$900
Best for: Most cats with painful ulcers, herpes-associated disease, ulcers that are not improving on basic care, or cases where the cause is not yet clear.
  • Comprehensive eye exam with fluorescein stain and repeat staining at rechecks
  • Topical antibiotic therapy tailored to exam findings
  • Pain control and e-collar
  • Antiviral treatment when herpesvirus is suspected, often oral famciclovir or compounded topical cidofovir based on your vet's plan
  • Evaluation for underlying causes such as foreign material, eyelid disease, or tear film problems
  • One or more recheck visits over 1-2 weeks
Expected outcome: Good in many cases, though healing time is more variable than with a simple scratch. Herpes-related ulcers may recur later even after the current ulcer heals.
Consider: Higher medication and recheck burden. Antiviral treatment and repeated exams add to the cost range. Some cats need several medications with different dosing schedules.

Advanced

$1,000–$3,500
Best for: Cats with deep ulcers, descemetoceles, melting ulcers, perforations, severe pain, or ulcers that have not responded to medical care.
  • Referral to a veterinary ophthalmologist
  • Advanced diagnostics for deep, infected, melting, or nonhealing ulcers
  • Intensive topical treatment, sometimes every few hours early on
  • Procedures or surgery such as debridement, conjunctival grafting, corneal grafting, or repair of a perforation
  • Sedation or anesthesia as needed
  • Close follow-up to monitor healing, scarring, and vision
Expected outcome: Guarded to fair for vision depending on depth and speed of treatment, but timely specialty care can often save comfort and sometimes preserve useful vision.
Consider: More intensive care, more visits, and a higher cost range. Even with treatment, some cats are left with scarring, reduced vision, or may need eye removal if the eye cannot be saved.

Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.

Questions to Ask Your Vet About Corneal Ulcers

Bring these questions to your vet appointment to get the most out of your visit.

  1. You can ask your vet: Is this ulcer superficial, deep, melting, or at risk of perforation? The ulcer's depth and stability guide urgency, treatment intensity, and whether referral is needed.
  2. You can ask your vet: Do you suspect feline herpesvirus, and if so, what treatment options make sense for my cat? Herpes-related ulcers often need a different plan than a simple traumatic scratch.
  3. You can ask your vet: What medications am I giving, how often, and what should I do if I miss a dose? Eye medications often need strict timing, and clear instructions improve the chance of healing.
  4. You can ask your vet: Should my cat wear an e-collar the whole time, even when supervised? Self-trauma can turn a mild ulcer into a much more serious one.
  5. You can ask your vet: What signs mean the ulcer is getting worse and I should come back sooner? Knowing the warning signs helps you act before the eye becomes unstable.
  6. You can ask your vet: When do you want to recheck the eye, and will you repeat the fluorescein stain? Rechecks are how your vet confirms the ulcer is truly healing.
  7. You can ask your vet: Are there underlying problems like an eyelid issue, foreign body, dry eye, or chronic corneal disease that also need treatment? If the cause is missed, the ulcer may recur or fail to heal.
  8. You can ask your vet: At what point would you recommend a veterinary ophthalmologist? A clear referral threshold helps you plan if the eye does not improve quickly.

Can Corneal Ulcers Be Prevented?

Not every corneal ulcer can be prevented, especially in cats with recurrent herpesvirus disease. Still, there are practical ways to lower risk. Keeping cats indoors reduces eye trauma from fights, brush, and debris. In multi-cat homes, reducing conflict and crowding may also help lower stress-related herpes flare-ups.

If your cat has a history of herpes-related eye disease, talk with your vet about what early signs to watch for and whether an antiviral plan makes sense during flare-ups. Evidence for supplements such as lysine has been mixed, so it is best to ask your vet before relying on them.

The biggest preventive step is early action. A red, watery, or squinting eye should be checked promptly. Fast treatment can keep a small surface injury from becoming a deeper, more painful problem.

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