Corneal Ulcers in Dogs: Causes, Treatment & Healing
- A corneal ulcer is an open sore on the clear front surface of the eye. It is painful, can worsen quickly, and should be checked by your vet the same day.
- Common causes include scratches, plant material, rubbing at the eye, dry eye, eyelid problems like entropion or abnormal eyelashes, and exposure-related injury in flat-faced breeds.
- Typical signs are squinting, tearing, redness, cloudiness, light sensitivity, discharge, and pawing at the face. A deep ulcer may look like a crater or white spot.
- Many superficial ulcers heal in about 5 to 7 days with medication and an e-collar, but indolent ulcers often need debridement and deep or melting ulcers may need urgent surgery.
- Do not use human eye drops unless your vet specifically says to. Steroid-containing eye medications can delay healing and may make an ulcer much worse.
What Are Corneal Ulcers?
The cornea is the clear outer surface of your dog’s eye. It helps protect the eye and plays a major role in focusing vision. A corneal ulcer happens when the surface layer is scraped away or when damage extends deeper into the cornea. Because the cornea has many nerve endings, even a small ulcer can be very painful.
Vets usually describe ulcers by depth and behavior. Superficial ulcers affect the outer layer and often heal quickly with medical care. Stromal ulcers extend deeper and carry a higher risk of scarring, infection, or rupture. A descemetocele means the ulcer has reached the last thin layer before perforation, and a perforated ulcer means the eye wall has opened. Those are emergencies.
Some dogs develop indolent ulcers, also called spontaneous chronic corneal epithelial defects or SCCEDs. These are superficial ulcers that do not stick down and heal normally. They are seen most often in middle-aged to older dogs and are especially common in Boxers. These ulcers often need a procedure, not medication alone, to heal well.
Another dangerous form is a melting ulcer. In these cases, enzymes from inflammation or infection start breaking down the corneal tissue, making the surface look soft or gelatinous. Melting ulcers can deepen fast, sometimes over hours to a day, so prompt treatment matters.
Symptoms of Corneal Ulcers
- Sudden squinting or holding one eye shut, which often signals significant pain
- Excessive tearing or wet fur below the eye
- Redness of the eye or pink tissues around it
- Cloudiness, haze, or a blue-white film over the cornea
- Pawing, rubbing, or face-scratching that can make the ulcer deeper
- Light sensitivity or reluctance to open the eye in bright rooms or outdoors
- Stringy mucus, yellow discharge, or thicker drainage that may suggest infection or dry eye
- Visible blood vessels growing onto the cornea, often seen with healing or chronic ulcers
- A visible pit, crater, or dark/clear bulge in the cornea, which can mean a deep ulcer or descemetocele
See your vet immediately if your dog is suddenly squinting, has a cloudy eye, or keeps rubbing at the face. Corneal ulcers are painful, and some can become much deeper very quickly. Same-day care is especially important if the eye looks blue or white, there is thick discharge, your dog will not open the eye, or you can see a dent or bulge on the cornea. If the eye looks collapsed, bleeding, or severely swollen, treat it as an emergency.
What Causes Corneal Ulcers?
Trauma is one of the most common causes. That can include a scratch from another pet, a cat claw, rough play, a twig or grass seed, grooming accidents, or rubbing the eye on carpet or furniture. Even a small surface injury can become a painful ulcer.
Some dogs are more vulnerable because of their anatomy. Brachycephalic breeds such as Pugs, English Bulldogs, Shih Tzus, Boston Terriers, and Pekingese have more prominent eyes and often do not blink as completely. That makes the cornea easier to dry out or injure. Eyelid problems like entropion, ectopic cilia, or distichia can also cause repeated rubbing on the cornea.
Medical conditions matter too. Dry eye (keratoconjunctivitis sicca, or KCS) reduces the protective tear film and increases the risk of painful ulcers, infection, scarring, and vision loss. Corneal dystrophy, exposure keratitis, facial nerve problems, and poor tear quality can also contribute.
In some cases, bacteria invade the damaged cornea and create a complicated or melting ulcer. These ulcers can progress rapidly and may threaten the eye itself. Indolent ulcers are different. They are usually not caused by active infection, but by poor attachment of the surface cells to the underlying cornea.
How Are Corneal Ulcers Diagnosed?
Your vet usually starts with a careful eye exam and a fluorescein stain. This orange dye sticks to exposed corneal tissue and glows bright green under blue light, helping show whether an ulcer is present and how large it is. This is the key test for many ulcers.
A full workup often includes checking the eyelids for hairs or foreign material, looking under the third eyelid, and measuring tear production with a Schirmer tear test. Your vet may also measure eye pressure with tonometry, although they may delay that test if the cornea looks extremely fragile.
If the ulcer is deep, infected, recurrent, or melting, your vet may recommend cytology and culture before starting or changing antibiotics. That helps guide treatment when resistant bacteria or severe infection is a concern. Deep ulcers and descemetoceles can be difficult to judge without magnification, so referral to a veterinary ophthalmologist may be recommended.
Typical diagnostic cost ranges in the U.S. are often about $100 to $350 for an exam, stain, tear test, and basic eye testing, with higher totals if culture, sedation, or specialist evaluation is needed.
Treatment Options for Corneal Ulcers
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Conservative: Medical care for uncomplicated superficial ulcers
- Eye exam and fluorescein stain
- Topical antibiotic drops or ointment to reduce infection risk
- Pain control, which may include atropine and/or oral pain medication if your vet feels it is appropriate
- E-collar to prevent rubbing
- Home medication 2 to 4 times daily in many cases
- Recheck stain in about 3 to 7 days
Standard: Procedure-based care for indolent or nonhealing ulcers
- Repeat eye testing and fluorescein stain
- Corneal debridement to remove loose, nonadherent epithelium
- Diamond burr debridement or grid keratotomy when your vet or ophthalmologist feels it is appropriate
- Bandage contact lens in selected cases
- Medication for comfort and infection prevention
- Treatment of underlying causes such as dry eye or eyelid disease
- One or more rechecks until the ulcer is closed
Advanced: Intensive medical care and surgery for deep, melting, or perforated ulcers
- Urgent or emergency ophthalmic assessment
- Frequent topical medications, sometimes every 1 to 2 hours at first
- Anti-collagenase therapy such as serum-based treatment when indicated
- Culture and targeted antibiotic therapy for infected ulcers
- Conjunctival graft, corneoconjunctival transposition, or other corneal support procedure
- Third eyelid flap or temporary tarsorrhaphy in selected cases
- Hospitalization or specialist follow-up for severe cases
- Enucleation as a pain-relief option 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.
- You can ask your vet: How deep is the ulcer, and is it superficial, stromal, melting, or close to perforating? Depth changes urgency, healing time, and whether medication alone is reasonable or surgery should be discussed.
- You can ask your vet: Do you suspect an underlying cause like dry eye, entropion, distichia, or exposure from my dog’s face shape? Treating the ulcer without addressing the cause can lead to delayed healing or repeat ulcers.
- You can ask your vet: How often do the eye medications need to be given, and what should I do if I miss a dose? Eye medications often work only when given on schedule, especially with infected or deeper ulcers.
- You can ask your vet: Does my dog need an e-collar the entire time, even when supervised? Rubbing can turn a manageable ulcer into a much more serious one very quickly.
- You can ask your vet: When should we recheck the eye with another fluorescein stain? A dog may seem more comfortable before the ulcer is actually healed, so recheck timing matters.
- You can ask your vet: Are there signs of infection that mean we should culture the ulcer or see an ophthalmologist? Culture and referral can be especially helpful for deep, melting, recurrent, or nonhealing ulcers.
- You can ask your vet: What warning signs at home mean I should come back sooner or go to emergency? Knowing what counts as worsening helps you act quickly if the eye becomes cloudier, more painful, or suddenly changes shape.
How to Prevent Corneal Ulcers
You cannot prevent every eye injury, but you can lower risk. Keep brush and sharp plants trimmed at eye level, supervise rough play, and be careful during grooming around the face. It is also safer to keep your dog’s head inside the car rather than letting them ride with the face in the wind, where debris can strike the eye.
If your dog is a brachycephalic breed, check the eyes often for redness, squinting, or discharge. These dogs are more prone to exposure-related irritation and trauma because their eyes are more prominent. Keeping facial folds and hair clean and trimmed can help reduce irritation.
If your dog has dry eye, use prescribed tear-stimulating medication exactly as directed. Dry eye is a major risk factor for painful ulcers and long-term corneal damage. Dogs with eyelid abnormalities may need a procedure to reduce repeated corneal rubbing.
Avoid using leftover pet eye medication or human eye drops unless your vet tells you to. Steroid-containing eye products can be especially risky if an ulcer is present. When in doubt, a same-day exam is safer than trying home treatment first.