Corneal Ulcer in Dogs

A corneal ulcer is an open sore on the cornea, the clear outer layer at the front of your dog’s eye. Even a small ulcer can be very painful because the cornea has many nerve endings. Dogs with ulcers often squint, keep the eye closed, rub at the face, or develop tearing and discharge. The eye may also look cloudy or red. Corneal ulcers can be superficial, deep, infected, slow-healing, or severe enough to threaten the structure of the eye.

This is not a condition to watch at home for long. Corneal ulcers can worsen fast, especially if there is trauma, dry eye, an eyelid problem, or infection. Your vet may recommend different levels of care depending on ulcer depth, healing progress, your dog’s comfort, and your family’s goals and budget. Early treatment often leads to a much smoother recovery and lowers the risk of scarring, rupture, or permanent vision loss.

Your vet usually starts with a careful eye exam, looking for redness, discharge, eyelid problems, foreign material, and signs of pain. The most common test for a corneal ulcer is a fluorescein stain. This dye sticks to damaged areas of the cornea and helps show whether an ulcer is present and how large it is. Your vet may also check tear production with a Schirmer tear test, because dry eye can cause ulcers or keep them from healing.

If the ulcer is deep, infected, or not healing as expected, your vet may recommend additional testing. That can include checking the eye pressure, examining the eyelids and eyelashes closely, or taking samples for cytology or culture in complicated cases. Some dogs need referral to a veterinary ophthalmologist, especially if the ulcer is indolent, melting, very deep, or at risk of perforation. Diagnosis is not only about finding the ulcer. It is also about finding the reason it happened so treatment can match the problem.

Corneal ulcers often start with trauma. A scratch from a branch, rough play, a cat swipe, debris, shampoo in the eye, or self-trauma from rubbing can damage the corneal surface. But trauma is only part of the story. Many ulcers happen because something keeps irritating the eye or prevents normal healing. Common examples include dry eye, eyelid abnormalities such as entropion, abnormal eyelashes rubbing the cornea, and foreign material trapped under the eyelid.

Some dogs are also prone to slow-healing or recurrent ulcers. Merck notes that superficial nonhealing ulcers in dogs are called indolent corneal ulcers or recurrent corneal erosions, and Boxers are commonly affected. Flat-faced breeds may also be at higher risk for eye surface injury because their eyes are more exposed. Infection can complicate an ulcer and make it much more serious. That is why your vet may look for underlying causes instead of treating the sore alone.

Not every corneal ulcer can be prevented, but many risks can be lowered. Keep your dog’s face and eyes clean, trim hair that pokes toward the eye if your vet or groomer recommends it, and use care with bathing so shampoo does not splash into the eyes. The ASPCA also advises safer car travel with windows only partly down and your dog’s head inside the vehicle to reduce injury from debris or insects.

Prompt care for eye discharge, dry eye, eyelid problems, and repeated squinting matters too. Dogs with flat faces, prominent eyes, or a history of ulcers may need closer monitoring. If your dog has chronic eye disease, follow your vet’s plan closely and do not stop eye medications early unless your vet says it is safe. Preventing repeat injury often depends on managing the underlying cause, not only the ulcer itself.

Many superficial corneal ulcers heal well when treated early. PetMD notes that treatment depends on ulcer type and severity, and many mild ulcers improve quickly with topical medication. During recovery, your dog should become more comfortable, with less squinting and discharge. Recheck visits are important because the eye can look better before the ulcer is fully healed.

The outlook becomes more guarded when an ulcer is deep, infected, melting, nonhealing, or perforated. Scarring, blood vessel growth, chronic pain, and vision loss are possible in more severe cases. Some dogs need procedures or surgery to save the eye. Even then, outcomes vary based on how quickly treatment starts and whether there is an underlying problem such as dry eye or eyelid disease. Your vet can help you balance comfort, vision goals, and cost range when planning next steps.