Corneal Ulcer in Cats: Symptoms and Healing Time

Name: Corneal Ulcer in Cats: Symptoms and Healing Time
Creator: Dr. Zubair Khalid

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-10-03

A corneal ulcer in cats is an open sore on the clear surface of the eye, and most superficial ulcers heal in about one to three weeks with proper treatment [1][2]. Healing time depends on how deep the ulcer is, what caused it, and whether the cat has an underlying condition like feline herpesvirus. Corneal ulcer in cats treatment almost always involves prescription eye drops or ointments, frequent rechecks, and sometimes surgery for deep or slow-healing sores.

This article is educational and is not a substitute for veterinary diagnosis or treatment.

Quick Answer

A corneal ulcer is a scratch or sore on the cornea, the clear window at the front of the eye. It is painful and needs veterinary care.
Never use leftover steroid eye drops on a cat with a red, squinting eye. Steroids can make a corneal ulcer much worse.
Most superficial ulcers heal in roughly 7 to 21 days with topical antibiotics and other prescription medication [3][1].
Deep ulcers, melting ulcers, and perforations take longer and often need surgery. One study of deep ulcers and perforations treated with stem cell injections found most became fluorescein-negative within 1 to 3 weeks [2].
Your vet will recheck the eye with a fluorescein stain, often every few days at first, until the ulcer is fully healed.

What Is a Corneal Ulcer in Cats?

The cornea is the clear, dome-shaped tissue over the colored part of the eye. Its outermost layer, the epithelium, is delicate. When cells are lost faster than the body can replace them, the result is a corneal ulcer [4]. The sore can stay on the surface (superficial) or extend into the deeper stroma. In severe cases it can go all the way through, causing a perforation that lets fluid drain from inside the eye. That can lead to blindness or loss of the eye [4].

Veterinarians often grade ulcers by depth. A common system classifies them as superficial (grade 1), stromal (grade 2), or descemetoceles and perforations (grade 3) [5]. This grading matters because it drives the treatment plan and the expected healing time.

Cats also get a related problem called a corneal sequestrum, a dark spot on the cornea that can form after chronic ulceration. In one review of 71 ulcers, corneal sequestration occurred in about 28 percent of cases [1]. Brachycephalic cats (flat-faced breeds like Persians and Himalayans) are more likely to develop ulcerative keratitis and sequestra than other cats [5].

Corneal Ulcer in Cats Symptoms

Owners usually notice something is wrong before they see the ulcer itself. Common signs include:

Squinting or holding the eye closed
Excessive tearing or discharge
Redness around the eye
Cloudiness or a blue-gray haze on the cornea
Pawing at the face or rubbing the eye
Sensitivity to light
A visible dark spot on the eye surface

Cats hide pain well, so a cat that is only slightly squinting may still have a significant ulcer. Any cat with a red, painful, or cloudy eye should be seen by a veterinarian. If your cat has a sudden eye injury, see Cat Eye Injury: When to See a Vet Immediately. For a broader look at eye conditions in cats, see Feline Ocular Diseases: Common Conditions and Treatment.

Corneal Ulcer in Cats Causes

Many things can damage the corneal surface. According to Cornell University's College of Veterinary Medicine, the most frequent cause is recurrent infection with feline herpesvirus (FHV) [4]. Most cats exposed to this virus are very young when they first encounter it [4].

Other causes include:

Scratches from fights with other cats [4]
Ingrown eyelashes or eyelid defects [4][3]
Foreign material trapped under the eyelid, such as dirt [4]
Exposure to caustic chemicals [4]
Bacterial or viral infection [4][3]
Eyelid shape problems that leave the cornea exposed [3]

Secondary bacterial infections are common and can make ulcers worse [3]. Ulcerative keratitis caused by feline herpesvirus-1 tends to heal slowly and can recur throughout the cat's life [3].

Some cats develop corneal erosion after general anesthesia, even with lubricating drops. In one study of 42 cats having non-eye procedures, about 27 percent of eyes developed corneal erosion afterward, and tear production dropped significantly for at least four hours after anesthesia [6]. This is one reason vets examine the eyes carefully after any procedure.

How Veterinarians Diagnose a Corneal Ulcer

Diagnosis starts with a full eye exam. Your vet will look at the eyelids, check for foreign material, and assess tear production. To find the ulcer, they place a drop of special dye (fluorescein) on the eye. The dye sticks to areas where the corneal surface is missing, so even small ulcers show up clearly [3].

Your vet may also:

Check for a corneal sequestrum, a dark plaque that can form on the cornea
Look for signs of herpesvirus, such as branching (dendritic) ulcers
Test for tear production with a Schirmer tear test
Examine the eyelids for rolled-in lashes or other defects

A dendritic corneal ulcer in cats is a branching sore pattern that is strongly associated with feline herpesvirus. These ulcers can be stubborn and may need antiviral medication in addition to antibiotics.

Why Steroid Drops Can Make an Ulcer Worse

This is one of the most important things for cat owners to understand. Topical corticosteroids reduce inflammation, and they are sometimes used for certain eye conditions. But if the cornea has an ulcer, steroids can slow healing and allow the ulcer to deepen or even perforate.

That is why you should never use eye drops prescribed for another pet, another person, or a previous episode without checking with your vet first. If your cat has a red, squinting eye, keep the eye lubricated with preservative-free artificial tears if your vet approves, and get to a veterinarian promptly.

Some eye conditions, such as eosinophilic keratitis, are treated with topical steroids or calcineurin inhibitors. In one study, cats with eosinophilic keratitis improved in a median of 16 to 19 days depending on the medication used [7]. The point is that steroids have a place in veterinary ophthalmology, but only when a vet has confirmed there is no ulcer.

Corneal Ulcer in Cats Treatment

Treatment depends on the depth, cause, and severity of the ulcer. Your veterinarian will tailor the plan to your cat.

Medical Treatment

Initial therapy usually involves removing dead, damaged, or infected tissue from the ulcer, followed by topical antibiotics and other prescription medication [3]. Your vet may prescribe:

Antibiotic eye drops or ointment to prevent or treat bacterial infection
Antiviral medication if herpesvirus is suspected
Pain medication, since ulcers are painful
Artificial tears or lubricants to keep the eye moist
Atropine to relieve painful eye spasms, if needed

The exact dose and frequency depend on your cat's weight, the medication chosen, and the severity of the ulcer. Your veterinarian will calculate the dose and show you how to apply the medication.

Surgical Treatment

Deep ulcers, melting ulcers, and perforations may need surgery. Options include:

Corneal debridement to remove loose tissue
Conjunctival grafts or flaps to support healing
Freeze-dried amniotic membrane transplantation. In one study of dogs and cats with deep melting ulcers, mean healing time after this surgery was 17 days [8].
Mesenchymal stem cell injections. In one study, 88 percent of cats with deep ulcers or perforations treated with stem cells became fluorescein-negative within 1 to 3 weeks [2].
Photoactivated chromophore for keratitis-corneal cross-linking (PACK-CXL), a procedure that uses a light-activated compound to strengthen the cornea. One study reported an overall healing success rate of 97 percent, with healing times ranging from 4 to 74 days [9].

A Note on Debridement

Cotton-tipped applicator debridement is a common technique to remove loose corneal tissue. One study found that ulcers were significantly more likely to undergo corneal sequestration after this type of debridement [1]. This does not mean debridement is wrong. It means your vet weighs the risks and benefits for each cat.

Healing Time and Rechecks

Healing time varies widely. Here is a general guide based on the available evidence:

Ulcer Type	Typical Healing Time	Notes
Superficial ulcer	About 7 to 21 days	Most heal with topical medication and rechecks [3][1]
Deep ulcer or perforation	About 1 to 3 weeks with advanced treatment	88 percent of cats in one stem cell study healed in 1 to 3 weeks [2]
Deep melting ulcer after surgery	About 17 days on average	Based on a study of dogs and cats treated with amniotic membrane [8]
Ulcer treated with PACK-CXL	4 to 74 days	Overall success rate was 97 percent in one study [9]

Your vet will recheck the eye with fluorescein staining, often every 3 to 7 days at first. The ulcer is considered healed when the dye no longer sticks to the cornea. Even after healing, some cats develop corneal vascularization (blood vessels growing into the cornea) or pigmentation. In one study, about 13 percent of ulcers developed corneal stromal vascularization after healing [1].

If your cat's ulcer is not healing as expected, your vet may adjust the treatment, test for underlying conditions, or refer you to a veterinary ophthalmologist.

Prevention and Long-Term Management

Some causes of corneal ulcers cannot be prevented, but you can lower the risk.

Keep your cat indoors to reduce fight-related scratches and exposure to other cats.
Treat herpesvirus flare-ups promptly. Cats with recurrent herpesvirus ulcers may need long-term management [3].
Avoid using any eye medication that was not prescribed for this cat for this episode.
Schedule regular vet visits for cats with flat faces, since brachycephalic cats have a higher risk of ulcerative keratitis [5].
Watch for squinting, redness, or discharge and call your vet early.

If your cat has a history of conjunctivitis or eye discharge, see Cat Eye Conjunctivitis Treatment. If your cat has a lip or skin sore that looks like an ulcer, that is a different problem. See How To Treat Rodent Ulcers In Cats.

Limitations and When to Contact a Veterinarian

This article gives general information. Every cat is different, and only a veterinarian who examines your cat can diagnose and treat a corneal ulcer.

Contact a veterinarian the same day if your cat:

Squints, holds the eye closed, or paws at the eye
Has a red, cloudy, or blue-gray eye
Has discharge from the eye
Has a known or suspected eye injury

Go to an emergency veterinary hospital immediately if:

The eye looks like it is bulging or has changed shape
There is blood or a visible wound on the eye
Your cat is in severe pain, crying, or unable to open the eye at all
You see a dark spot or hole on the cornea
Your cat suddenly cannot see

Do not wait to see if the eye gets better on its own. Corneal ulcers can worsen quickly, and a perforation can lead to blindness or loss of the eye [4].

Frequently Asked Questions

How long does a corneal ulcer take to heal in cats?

Most superficial corneal ulcers heal in about one to three weeks with treatment. Deeper ulcers or those caused by herpesvirus can take longer and may need surgery or advanced therapies. Your vet will confirm healing with a fluorescein stain at recheck visits.

Can a corneal ulcer in cats heal on its own?

No, a corneal ulcer should not be left to heal without veterinary care. Even superficial ulcers are painful and can become infected or deepen. Without treatment, an ulcer can progress to a perforation, which can cause blindness or loss of the eye.

What does a dendritic corneal ulcer look like in cats?

A dendritic ulcer has a branching, tree-like pattern that is visible with fluorescein dye. This pattern is strongly associated with feline herpesvirus. These ulcers often need antiviral medication along with antibiotics and can recur throughout the cat's life.

Are some cat breeds more prone to corneal ulcers?

Yes. Brachycephalic breeds, such as Persians and Himalayans, have a higher prevalence of ulcerative keratitis and corneal sequestra than other cats. Their eye shape and eyelid anatomy can leave the cornea more exposed and prone to injury.

Can I use steroid eye drops on my cat's red eye?

No. Never use steroid eye drops on a cat with a red or squinting eye unless a veterinarian has examined the eye and confirmed there is no ulcer. Steroids can make a corneal ulcer worse and can lead to perforation. Call your vet before using any eye medication.

References

Spontaneous Superficial Ulcerative Keratitis in Client-Owned Cats: Risk Factors for Delayed Healing, Corneal Sequestration, or Corneal Stromal Vascularization. Veterinary ophthalmology, 2026.
Efficacy of mesenchymal stem cell therapy for treating deep corneal ulcers and corneal perforation in cats: a retrospective study. Journal of feline medicine and surgery, 2026.
Disorders of the Cornea in Cats - Cat Owners. Merck Veterinary Manual.
Corneal Ulcers. Cornell University College of Veterinary Medicine.
Prevalence and Characteristics of Feline Ulcerative Keratitis and Corneal Sequestra in a Referral Population and Comparison Between Brachycephalic and Nonbrachycephalic Cats. Veterinary ophthalmology, 2026.
Impact of general anesthesia on feline aqueous tear production and the feline corneal epithelium. Journal of feline medicine and surgery, 2025.
Initial Outcomes Following Treatment With Topical Corticosteroids or Topical Calcineurin Inhibitors in Cats With Eosinophilic Keratitis. Veterinary ophthalmology, 2026.
Surgical Repair of Deep Melting Ulcers With Freeze-Dried Amniotic Membrane Transplantation in Dogs and Cats. Veterinary ophthalmology, 2026.
Photoactivated chromophore for keratitis-Corneal cross-linking in dogs and cats: A retrospective study in Italy. Veterinary ophthalmology, 2025.