You notice your dog blinking more than usual. Maybe pawing at their eye. When you look closer, there’s a cloudy patch on the surface. They turn their head away from the light. It doesn’t look serious, but they’re clearly uncomfortable.
Corneal ulcers can start small. Just a surface scratch, sometimes from rough play or a speck of debris. But if left untreated, they can get worse quickly. Infection can set in. The tissue can break down. In serious cases, it can cost a dog their vision.
That’s why timing matters. The faster we catch it, the better the chances for healing without long-term damage.
This guide outlines what to watch for, what causes corneal ulcers, and how we handle treatment here at Noble Vet Clinics.
What Is a Corneal Ulcer in Dogs, and Why Does It Matter?
The cornea is the transparent, outermost layer of your dog’s eye. Think of it like a windshield: smooth, delicate, and essential for clear vision. A corneal ulcer is a break in that surface, exposing the sensitive layers beneath. It might be shallow at first, but without treatment, ulcers can deepen, become infected, or even rupture.
And unlike a limp or a skin rash, eye pain is harder to ignore. Dogs often exhibit symptoms such as squinting, light sensitivity, or constant blinking. In severe cases, they may shut the eye entirely.
What Are the Signs of a Corneal Ulcer in Dogs?

Ulceration includes both visible and behavioral signs that may develop suddenly or over time. You know your dog. When something’s off, you feel it. But when it comes to eyes, here’s what you should watch for:
Redness or swelling around the eye, sometimes accompanied by dilated blood vessels on the sclera
Tearing or unusual discharge (clear, yellow, or green)
Pawing at the face or rubbing on furniture
Cloudiness or a visible white spot on the eye
Sensitivity to light
Even if symptoms seem subtle, they can escalate quickly. If your dog shows any of these signs, don’t wait.
What Causes Corneal Ulcers in Dogs?
There isn’t just one cause. Corneal ulcers can show up for a lot of reasons. Sometimes it’s obvious. Other times, it’s not.
Injury. A scratch from a branch. A swipe during play. Even a bit of grit from the wind. Any of these can damage the outer layer of the cornea.
Dry eye (keratoconjunctivitis sicca). If your dog isn’t producing enough tears, the cornea dries out. That makes it more likely to crack or erode.
Foreign material. Dust, fur, or seeds can irritate if they get caught under the eyelid and scrape across the eye, potentially leaving a mark.
Eyelid problems. Some dogs have lids that turn inward (entropion) or grow extra lashes (distichiasis). These rub against the eye and wear it down over time.
Infection. If the surface is already injured, bacteria or fungi can get in. That makes healing harder and can speed up the damage. Viral infections can complicate things even further.
How Do Breed and Facial Structure Influence Ulcer Risk?
Some dogs are just built in a way that puts their eyes at higher risk. Pugs, Bulldogs, Shih Tzus, any breed with a flatter face and bulging eyes tends to run into more problems. The eyes stick out more, they don’t always close fully, and tears don’t spread evenly across the surface.
There’s data to back that up. A large UK study tracked over 100,000 dogs and found that while corneal ulcers were pretty rare overall, they were much more common in certain breeds. Pugs had rates over 5%, Boxers about the same, and Shih Tzus close behind. Purebreds in general had double the risk. And if they were flat-faced? More than 11 times the odds.
Another cross-sectional study of 700 dogs analyzed facial structure and found a direct correlation with ulcer risk. Dogs with very short skulls, like extreme brachycephalics, were shown to be 20 times more likely to get corneal ulcers. Just having deep nasal folds made the risk nearly five times higher. And even a small change, like the eyelids being just 10% more open than average, tripled the chances of injury to the layer of cells covering the cornea.
These findings highlight how subtle anatomical traits, often overlooked, can have a dramatic influence on eye health.
How Do Vets Diagnose Corneal Ulcers?
Diagnosis starts with a thorough eye exam. The most telling test? Fluorescein staining. This harmless dye sticks to damaged areas of the cornea, glowing green under blue light. From there, we assess depth, severity, and whether the ulcer is infected or at risk of perforation.
If dry eye is suspected, we measure tear production to confirm the diagnosis. In advanced cases, we may swab for cultures to identify the specific bacteria or fungi involved.
Are There Different Types of Corneal Ulcers?
Yes. Not all ulcers in dogs are the same, and some are much more serious than others. The most common types of ulcer we see include:
Type of Ulcer | Description |
Superficial Ulcer | Affects only the outermost layer; typically heals quickly with medication. |
Stromal Ulcer | Deeper and more painful, may require aggressive treatment to prevent scarring. |
Indolent Ulcer | Also called "non-healing" ulcers or spontaneous chronic corneal epithelial defect (SCCED), require debridement or keratotomy. |
Descemetocele | Ulcer has reached the deepest layer; urgent surgery needed to save the eye. |
Perforated Ulcer | Full rupture of the cornea; often requires surgical repair or graft. |
How are Corneal Ulcers in Dogs Treated?

Treatment depends on the type and severity of the ulcer. Here’s how we typically approach it:
Medication: For many superficial ulcers, we start with antibiotic drops or ointments to prevent infection, plus steroidal anti-inflammatory drops only when appropriate. If the ulcer is deeper or looks like a melting ulcer, we escalate treatment accordingly.
E-Collar: To stop self-trauma. No exceptions here. Your dog’s paws will only make it worse.
Procedures for Non-Healing Ulcers: Grid keratotomy or diamond burr debridement can help indolent ulcers heal.
Surgery: Deep ulcers or descemetoceles may need conjunctival grafts or corneal flaps to preserve vision and prevent loss of the eye
The key? Follow-up. Healing eyes need monitoring. We adjust medications based on progress and retest as needed.
How Long Does It Take for a Corneal Ulcer to Heal?
Ulcer Type | Estimated Healing Time |
Simple/Superficial | 3 to 7 days |
Indolent/Infected | 10 days to several weeks |
Surgical/Deep | Several weeks, plus follow-up visits |
Healing time varies by age, underlying health, and whether complications arise. Some dogs heal quickly. Others need time, patience, and repeated checks.
What Happens If It’s Left Untreated?
Corneal ulceration occurs quietly at first, but untreated ulcers rarely stay the same. They worsen over time. Infection can eat into deeper layers of the cornea. The surface may melt or rupture. Pain intensifies. And eventually, blindness becomes a real possibility.
It’s not worth the risk. Acting early can preserve your dog’s sight and spare them unnecessary pain.
Can You Prevent Corneal Ulcers?
You can’t prevent every ulcer, but there’s a lot you can do to reduce the risk.
Start by keeping the face clean, especially if your dog has big, exposed eyes or deep skin folds. A quick daily wipe can help remove debris before it causes trouble.
During hikes or car rides, think about eye protection. A hanging branch or a gust of sand can do more damage than you'd expect.
Schedule regular eye exams, especially for high-risk breeds.
Treat dry eye, keratoconjunctivitis sicca, or eyelid conditions early before damage sets in.
How We Treat Corneal Ulcers at Noble Vet Clinics
At Noble Vet, we combine medical precision with genuineness. Our vets use advanced diagnostic tools like slit-lamp exams and fluorescein testing to assess each case in detail. For deeper or complex ulcers, we offer minor surgical procedures and collaborate with veterinary ophthalmologists when needed.
But beyond that, we listen. Because we know how stressful it is to see your dog hurting, especially when the cause isn’t obvious. Our mission is to treat not just the eye, but the worry behind it.
“Healthy eyes mean a happy dog. Clear vision helps them explore and connect with the rest of the world.”
- Dr. Nenad Misura
The Takeaway for Pet Parents
A corneal ulcer may start small, but the consequences can be big. The sooner you act, the better the outcome. If your dog is showing signs of eye discomfort, don’t wait it out. Let us take a closer look.
At Noble Vet Clinics, we’re here to preserve not only your dog’s vision but their quality of life.
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