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If Your Dog Can’t Keep Its Eyes Open — Causes of Corneal Ulcers and When to Visit the Vet

Eye HealthQ&AMeongsiljang Veterinary Advisory Board

Corneal ulcers in dogs are a painful eye condition that requires prompt treatment. Here’s a summary of the key information pet owners should know.

Corneal Ulcers in Dogs Are a Condition Where the Eye Surface Is Damaged

A puppy with its eyes closed, appearing to be in discomfort.

Corneal ulcers in dogs are a condition where the cornea, the outermost layer of the eye, is scratched or damaged. This condition causes significant pain and requires prompt treatment. In the early stages, symptoms may include frequent blinking, excessive tearing, and rubbing of the eyes. These behaviors indicate that the eye is painful or irritated, and if left untreated, the cornea can become deeply damaged or infected. In severe cases, there is a risk of vision loss or even rupture of the eye. Immediate veterinary care is essential, as accurate diagnosis and treatment are crucial. Early intervention significantly impacts recovery.

The Main Causes of Corneal Ulcers Are Trauma and Infection

The most common causes of corneal ulcers in dogs are trauma from hair or small foreign bodies entering the eye, as well as scratches or injuries from claws. Brachycephalic breeds, with their short snouts and protruding eyes, are at higher risk because the center of the cornea is more exposed. Other potential causes include abnormally growing eyelashes that touch the cornea (distichiasis or ectopic cilia), keratoconjunctivitis sicca (KCS, or dry eye), eyelid malformations, neurological conditions such as facial nerve paralysis, and viral infections like feline herpesvirus (FHV). These factors can weaken the cornea’s protective barrier, leading to ulcer formation. Identifying the exact cause is crucial for effective treatment, so it’s important to work closely with your veterinarian to carefully analyze the underlying issue.

A close-up image of a wound on a dog's eye

The Main Symptoms of Corneal Ulcers Are Tearing, Redness, and Squinting

The most common signs of a corneal ulcer in dogs include excessive tearing, redness of the eye, and frequent blinking. You may also notice your dog rubbing its eyes or face. In more severe cases, a white spot may appear on the eye, or vision may seem cloudy. All of these symptoms indicate pain or irritation in the eye and should never be ignored. It’s important to visit a veterinarian right away for an accurate diagnosis. Early detection significantly improves the chances of successful treatment.

Signs That Require Immediate Veterinary Care

If your pet’s eyes are completely shut, excessively tearing, appearing cloudy, or showing white spots, seek veterinary care immediately. These signs suggest deep corneal damage or an infection. Delaying treatment can lead to vision loss or even rupture of the eye.

Comparison of Symptoms and Treatment Approaches by Severity of Corneal Ulcers

Item	Mild	Moderate	Severe
Symptoms	Slightly closing the eye, mild tearing	Excessive tearing, frequent eye closing, continuous tearing	Eye completely closed, tears flowing, white spots clearly visible
Treatment method	1–2 types of eye drops, 1–2 weeks of observation	Eye drops + topical antibiotics, 2–4 weeks of treatment	Deep ulcers require surgical treatment such as conjunctival flap grafting and intensive topical antibiotic treatment
Prognosis	Full recovery possible	High chance of recovery	Possibility of vision loss

It is important to get a diagnosis before symptoms worsen.

Diagnosis Is Confirmed with a Fluorescein Stain Test

Veterinarians accurately diagnose corneal ulcers in dogs using a fluorescein stain test. This dye does not adhere to healthy corneal epithelium but binds only to the exposed stroma where the epithelium has been stripped away. When illuminated with cobalt blue light, the damaged area fluoresces a bright green, allowing for precise determination of the ulcer’s location and extent. This test is very safe and provides immediate results, aiding in the development of an effective treatment plan. As a standard diagnostic procedure in veterinary clinics, it is essential to perform this test before initiating treatment, as therapy without an accurate diagnosis may be ineffective.

A veterinarian performing fluorescein staining on a puppy's eye.

Treatment Involves Medication and Management

Treatment for corneal ulcers primarily involves antibiotic eye drops to prevent or treat secondary bacterial infections. In cases where the ulcer is deep or progressing rapidly, surgical intervention such as a conjunctival flap graft may be necessary. It is crucial to fit your dog with an Elizabethan collar during treatment to prevent them from scratching or rubbing their eye. Administer medication strictly at the prescribed times and do not discontinue it arbitrarily. In particular, steroid eye drops should never be used without a veterinarian’s prescription, as they can delay wound healing and worsen the ulcer. Regular follow-up examinations are essential, and keeping the area around the eye clean throughout the treatment period aids in recovery.

Key Management Points for Pet Owners

- Monitor eye-related signs: If your pet frequently squints or rubs its eyes, seek veterinary care immediately. - Use an Elizabethan collar: During treatment, keep an Elizabethan collar (e-collar) on to prevent scratching or rubbing the eyes. - Administer medication as prescribed: Give medication at the scheduled times and do not stop it without veterinary guidance. - Maintain a clean environment: For breeds prone to hair or debris getting into the eyes, regularly wipe the area around the eyes. - Attend follow-up visits: Visit the clinic regularly during the treatment period to monitor recovery progress. - Provide a calm environment: Reduce stress and allow your pet to rest in a quiet space. All of these care measures play a crucial role in speeding up recovery.

A guardian gently wiping around their dog’s eyes.

Actions to Absolutely Avoid

If you suspect a corneal ulcer, never use antibiotic or steroid eye drops on your own. In particular, steroids can worsen the ulcer and even cause the eye to rupture. Using medication without a veterinarian’s prescription can pose serious risks.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

There’s a white spot on my puppy’s eye. Is it something to worry about?

No, it’s not fine. This could be a sign of a corneal ulcer. You should consult a veterinarian immediately.

Can corneal ulcers be completely cured?

In most cases, with proper treatment, full recovery is possible. However, delayed treatment can lead to vision loss.

Can it be prevented?

Yes, breeds with prominent eyes, such as brachycephalic dogs, require extra care because their corneas are more exposed. Regularly wipe away hair and debris around the eyes to prevent them from touching the cornea. If underlying issues such as distichiasis (abnormal eyelashes), eyelid malformations, or keratoconjunctivitis sicca (KCS, dry eye) are present, early management in consultation with a veterinarian can help prevent complications.

How long does the treatment period last?

Mild cases typically resolve within 1 to 2 weeks, moderate cases take 2 to 4 weeks, and severe cases may require several weeks to several months for recovery.

My dog seems uncomfortable wearing a collar. What should I do?

At first, your pet may feel a bit uncomfortable. However, since this is essential for their treatment, it's important to help them gradually adjust.

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References

[1] Carter, J. (2023). 100 Top Consultations in Small Animal General Practice. Elsevier.

[2] The Veterinary Workbook of Small Animal Clinical Cases. (2022). Elsevier.

[3] Clinical Atlas of Canine and Feline Ophthalmic Disease, 2nd Ed. (2021). Wiley-Blackwell.