Corneal Ulcers in Dogs: Symptoms and Treatment

By Tailwisp Editorial TeamUpdated October 17, 20263 min read

A squinting dog with a watery eye may have a scratch on the cornea, and timing matters.

What it is

The cornea is the clear front surface of the eye. An ulcer is a loss of the outer layer. Because the cornea has many nerves, ulcers are painful. Deeper ulcers can threaten the eye.

Causes

• Trauma: scratches from plants, claws or play
• Foreign material under the eyelid
• Dry eye. See dry eye in dogs
• Eyelid or lash abnormalities
• Infection
• Chemical irritation
• Flat-faced anatomy with prominent eyes. See health issues in flat-faced breeds

Signs

• Squinting or holding the eye closed
• Tearing or discharge
• Redness
• Cloudy or bluish spot
• Pawing at the eye
• Light sensitivity

Diagnosis

Your vet applies fluorescein stain, which highlights an ulcer under blue light. They may check tear production and eye pressure and look for causes such as foreign objects.

Treatment

• Antibiotic drops or ointments to prevent infection
• Pain relief and medications to relax eye spasms
• A cone to prevent rubbing
• Treating underlying causes
• Surgery for deep, non-healing or infected ulcers, such as grafts or procedures to support healing
• Rechecks to confirm healing

Steroid drops can make ulcers much worse, so never use them without a vet's direction.

Slow-healing ulcers

Some dogs develop ulcers that do not heal normally, especially older dogs and boxers. These often need special treatment. Your vet may refer you to an eye specialist.

At home

1. Keep the cone on at all times.
2. Give medication on time.
3. Keep the eye clean. See how to clean dog eyes safely.
4. Limit rough play and avoid dusty areas.
5. Return for rechecks.

Warning signs

Contact your vet right away if the eye gets cloudier, the pain increases, discharge becomes thick or the eye bulges.

Prevention

Trim hair around the eyes, supervise in brush, treat dry eye and eyelid problems and avoid letting dogs ride with their heads out the window. See how to trim hair around a dog's eyes.

Related conditions

Redness and discharge have many causes. See dog conjunctivitis and why is my dog's eye red or discharging.

Common mistakes

• Waiting to see.
• Using human drops.
• Removing the cone.
• Skipping rechecks.

Troubleshooting

• The eye still looks cloudy: the cornea may take time to clear, so ask your vet.
• My dog hates the cone: see dog cone alternatives.
• The ulcer came back: ask about underlying causes.

A simple plan

1. See a vet promptly.
2. Treat as directed.
3. Prevent rubbing.
4. Recheck.

Real-life examples

A lab scratches his eye on a branch, and drops heal it in days. A pug develops a deep ulcer and needs surgery. A boxer with a slow-healing ulcer improves with specialized care. Quick care saves eyes.

Taking it seriously

Eye pain is not a minor matter. Treat squinting as a reason to call your vet.

How ulcers heal

The cornea heals from the edges inward, and simple ulcers often close within days with treatment. Scarring may remain as a faint haze. Deeper ulcers take longer and may need surgery. Your vet will recheck with stain to confirm healing before reducing medication.

Why the cone matters

A dog who rubs a healing ulcer can reopen it or cause infection. Keep the cone on, even if the eye looks better. If your dog cannot cope with a hard cone, ask your vet about soft alternatives that still protect the eye.

Breed and anatomy risks

Dogs with prominent eyes, such as pugs and Pekingese, are prone to injuries. Extra care outdoors and regular eye checks help reduce risk.

The takeaway

Corneal ulcers need prompt treatment and a cone. Avoid human drops and follow rechecks.

This article is general educational information, not veterinary advice. Every dog is different. If your dog is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.