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Corneal ulcer in Dogs

Author: Dr. med. vet. Gisa Löwe | Last modified: 17.02.2026

When to visit the vet?

Urgent see a veterinarian within 24 hours

RED for deep or "melting" ulceration, severe pain, rapid worsening, milky cloudiness, purulent discharge, trauma, or suspected perforation.

Unsure about what’s wrong with your pet? Feel free to use our Symptom Checker for more clarity

Definition

A corneal ulcerAn ulcer is an open wound or erosion of the skin or mucous membrane that often heals poorly and can be caused by a variety of factors, including infections and chronic inflammatory conditions. on the eye, also known as an ulcerAn ulcer is an open wound or erosion of the skin or mucous membrane that often heals poorly and can be caused by a variety of factors, including infections and chronic inflammatory conditions., is a painful lesion or wound on a dog’s cornea that can be caused by a variety of factors. This condition requires prompt medical care to prevent permanent eye damage or loss of vision.

Can Occur with the Following Diseases:

Basics and possible causes

The cornea is the clear, protective outer layer of the eye that lets in and focuses light. It consists of several layers, and an ulcerAn ulcer is an open wound or erosion of the skin or mucous membrane that often heals poorly and can be caused by a variety of factors, including infections and chronic inflammatory conditions. develops when one or more of these layers are damaged. An injury to the cornea often leads to an ulcerAn ulcer is an open wound or erosion of the skin or mucous membrane that often heals poorly and can be caused by a variety of factors, including infections and chronic inflammatory conditions.. Such injuries can be caused by foreign objects like dust, sand, or plant material that get into the eye and irritate or scratch the sensitive surface of the cornea.

Another common cause of corneal ulcers is bacterial or viral infectionA viral infection occurs when a virus enters the body and infects healthy cells, which can lead to disease symptoms. The severity and type of symptoms can vary depending on the type of virus.. BacteriaBacteria are microscopic, single-celled organisms that exist in almost every environment on Earth. Some types of bacteria are beneficial or even essential to life, while others can cause disease. such as staphylococci or streptococci can triggerA trigger is a stimulus that elicits a specific reaction or state. In veterinary medicine, this can refer to emotional responses, such as fear or aggression, or medical conditions, such as seizures in dogs and cats. an infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. if the eye is already weakened by an injury. In some cases, fungal infections can also play a role. Viruses, especially canineCanine refers to anything related to dogs. The term is used to describe characteristics, diseases, or specific aspects that specifically affect dogs. herpesvirus, can also damage the cornea and lead to ulcers.

Certain breeds have a higher risk of corneal ulcers due to their anatomical features. This includes brachycephalic dogs like pugs or bulldogs, whose eyes are more prominent and therefore more easily injured. Dogs with incomplete eyelid closure or an abnormal lid position are also at greater risk.

Autoimmune diseasesAutoimmune diseases are conditions in which the immune system mistakenly attacks the body's own cells or tissues as if they were foreign substances. Examples in dogs and cats include autoimmune hemolytic anemia and systemic lupus erythematosus., where the dog’s immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. attacks its own eye cells, can also cause ulcers. Additionally, chemical irritants such as shampoos or sprays can damage the cornea, especially if they get into the eye.

Typical accompanying symptoms

Clouding of the cornea: The affected area on the cornea may appear cloudy or whitish, indicating damage.
Redness and Swelling: The eye may be red due to the inflammation, and the tissue around the eye may appear swollen.
Heavy eye discharge: A watery or purulentPurulent refers to pus or the production of pus, which may indicate a bacterial infection. Purulent inflammatory conditions are often painful and may have significant swelling and redness. discharge can occur from the affected eye, often a sign of an infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease..
Blinking or closing the eye: The dog may be constantly blinking or keeping the affected eye closed due to the Pain.
Increased rubbing of the eye: The dog may try to rub the eye with its paw or rub its head on furniture to relieve the Itching or Pain.
Behavioral changes: Due to the Pain and discomfort, the dog may be restless, eat less, or withdraw.

When to see a vet?

A visit to the vet is essential as soon as a corneal ulcerAn ulcer is an open wound or erosion of the skin or mucous membrane that often heals poorly and can be caused by a variety of factors, including infections and chronic inflammatory conditions. is suspected. Since the cornea plays an important role in protecting the eye, untreated ulcers can quickly lead to more serious complications, such as a perforationA perforation is a rupture or hole in the wall of a hollow organ, such as the gastrointestinal tract or bladder, which can lead to the release of contents into the body and severe infection. Perforations are Emergencies that require rapid veterinary intervention in dogs and cats. of the cornea or permanent vision damage.

A veterinarian should be consulted immediately, especially if there are signs of heavy discharge, obvious Pain, clouding of the cornea, or behavioral changes. Early therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. can speed up healing and minimize the risk of long-term damage.

Even if symptoms temporarily subside, it is important to get a professional diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and treatment, as the underlying problem may remain unresolved and could recur.

Symptom recognition for the pet owner and veterinary diagnostic procedure

For pet owners, observing the symptoms described above is the first step in recognizing a corneal ulcerAn ulcer is an open wound or erosion of the skin or mucous membrane that often heals poorly and can be caused by a variety of factors, including infections and chronic inflammatory conditions.. If suspected, the affected eye should be examined closely, but without causing additional pressure or irritation.

The vet will perform a thorough eye examination, which often includes a slit-lamp exam to look at the structure of the cornea in detail. Fluorescent dyes can be applied to the cornea to make defects or ulcers visible that are not recognizable to the naked eye.

In some cases, additional tests may be necessary to determine the cause of the ulcerAn ulcer is an open wound or erosion of the skin or mucous membrane that often heals poorly and can be caused by a variety of factors, including infections and chronic inflammatory conditions.. These include swabs to identify bacterial infections or viralViral refers to viruses and their effects on the organism. Viral infections in dogs and cats can range from harmless colds to severe, life-threatening diseases. pathogens, as well as examinations for possible systemic causes or autoimmune diseasesAutoimmune diseases are conditions in which the immune system mistakenly attacks the body's own cells or tissues as if they were foreign substances. Examples in dogs and cats include autoimmune hemolytic anemia and systemic lupus erythematosus..

What the pet owner can do and professional therapy options

As a first step for relief, the pet owner should prevent the dog from further injuring the affected eye. Wearing a protective collar, also known as a cone or “Elizabethan collar,” can prevent the dog from scratching or rubbing the eye.

It is important to keep the eye clean and avoid contaminationContamination refers to the pollution of surfaces, objects, water, food, or air with harmful microorganisms, chemicals, or other hazardous substances.. However, the pet owner should never use medications or eye drops on their own without veterinary instructions, as these can worsen the condition.

After the veterinary examination, the vet will prescribe appropriate medications, which may include antibiotic or antiviral eye drops. Occasionally, pain-relieving therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. may also be necessary to improve the animal’s well-being.

Adherence to the treatment plans recommended by the vet and regular follow-up exams are crucial for the successful healing of the corneal ulcerAn ulcer is an open wound or erosion of the skin or mucous membrane that often heals poorly and can be caused by a variety of factors, including infections and chronic inflammatory conditions.. The pet owner should follow the vet’s instructions exactly and report any changes or worsening of symptoms immediately.

Outlook on current research

Research in the field of corneal ulcers in dogs focuses on improving diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and treatment options. Recent studies are investigating the effectiveness of various topicalTopical refers to the direct application of medications or treatments to the skin or mucous membranes for a local effect, without being absorbed into the body. medications to speed up the healing of corneal ulcers. For example, research is being conducted on how hyaluronic acid-based eye drops can promote corneal regeneration. These substances show promising results in reducing inflammatory conditions and improving the eye’s moisture barrier.

Another exciting area of research is the use of stem cell therapies. Scientists are investigating whether mesenchymal stem cells, obtained from fatty tissue or bone marrow, can support the healing of corneal ulcers. InitialInitial means beginning or at the start. In medicine, it can refer to the first symptoms of a disease or the first phase of a treatment process. results suggest that these cells could promote the regeneration of damaged tissue by releasing anti-inflammatory substances and stimulating the formation of new corneal cells.

Genetic studies are trying to better understand the predispositionA predisposition is an innate inclination or susceptibility of an organism to certain diseases or conditions. In dogs and cats, there may be a genetic predisposition to certain conditions such as hip dysplasia or certain heart diseases. of certain dog breeds to corneal ulcers. Researchers are analyzing genetic markers to determine which genetic factors increase the risk of developing this eye disease. In the future, this could support targeted breeding strategies to reduce the occurrence of corneal ulcers in affected breeds.

Another research approach is the improvement of diagnostic imagingDiagnostic imaging includes medical procedures that create images of the inside of the body to diagnose, monitor, or treat diseases and injuries. Examples include X-ray, ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). techniques. Modern technologies such as confocal microscopy allow for a detailed view of the corneal structure, enabling more precise diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and treatment planning. These advanced imaging procedures help veterinarians better assess the severity and depth of the ulcerAn ulcer is an open wound or erosion of the skin or mucous membrane that often heals poorly and can be caused by a variety of factors, including infections and chronic inflammatory conditions., leading to more targeted and individualized treatment plans.

The investigation of the role of microorganisms in the development and worsening of corneal ulcers is also an active field of research. Scientists are analyzing the eye’s microbiota to determine which bacteriaBacteria are microscopic, single-celled organisms that exist in almost every environment on Earth. Some types of bacteria are beneficial or even essential to life, while others can cause disease. or fungal species are associated with the development of ulcers. These studies could lead to new antimicrobialAn antimicrobial substance is an agent that serves to inhibit the growth of microorganisms such as bacteria, viruses, fungi, and protozoa, or to kill them. Antimicrobials are frequently used to treat infections. treatment approaches specifically aimed at fighting the identified pathogenic microorganisms.

New therapeutic approaches, such as the use of antibody-based therapies, are also being explored. These treatments aim to neutralize specific inflammatory molecules in the eye that contribute to the worsening of corneal ulcers. Such targeted therapies could speed up healing and reduce the risk of complications.

In summary, current research offers a variety of promising approaches to improve the diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and therapyTherapy refers to the treatment of diseases or disorders with the aim of alleviating symptoms, promoting healing, or improving quality of life. Therapies can be medicinal, surgical, or through other medical interventions. of corneal ulcers in dogs. These advances could lead to improved clinical outcomes and a higher quality of life for affected dogs in the near future.

Frequently asked questions

1. What is a Corneal ulcer on the eye in dogs?

A corneal ulcer is an open wound on the cornea of the dog's eye. It results from damage to the cornea and can be very painful because the cornea has many nerve endings.

2. What symptoms does a dog with a Corneal ulcer on the eye show?

The most common symptoms include increased blinking, watery eyes, redness of the eye, sensitivity to light, and a cloudy or milky area on the cornea. The dog may also try to scratch or rub at the eye.

3. How is a Corneal ulcer on the eye diagnosed?

Diagnosis is usually made through a thorough ophthalmic examination by a veterinarian. The vet can use special dyes like fluorescein to make the ulcer visible under UV light and assess the depth and size of the ulcer.

4. What are the typical treatments for a Corneal ulcer on the eye?

Treatment can include topical antibiotics, eye drops for pain relief, and anti-inflammatory medications. In severe cases, surgical intervention may be necessary, such as the removal of dead tissue or placing a protective flap over the ulcer.

5. Can a dog with a Corneal ulcer on the eye go blind?

Yes, if a corneal ulcer remains untreated or worsens, it can lead to a perforation of the cornea and result in permanent vision loss or even blindness in the affected eye.

6. How long does it take for a Corneal ulcer on the eye to heal?

The healing time depends on the severity of the ulcer. Small ulcers can heal within one to two weeks, while more severe or complicated ulcers can take several weeks to months to heal completely.

7. What can be the causes of a Corneal ulcer on the eye?

Causes can include traumas (such as scratches or a foreign body in the eye), infections, dry eyes, genetic predispositions, or other eye diseases. Certain dog breeds are more prone to corneal ulcers.

8. Can a Corneal ulcer on the eye heal on its own?

Smaller ulcers can sometimes heal on their own, but it is important that they are monitored by a vet to avoid complications. Early diagnosis and therapy are crucial to minimize the risk of permanent damage.

9. Which dog breeds are particularly susceptible to corneal ulcers?

Breeds with protruding eyes, such as pugs, bulldogs, and Shih Tzus, are particularly prone to corneal ulcers. Their eyes are often less protected and more susceptible to injury and dryness.

10. Are there preventive measures against corneal ulcers?

Regular eye exams at the vet, avoiding situations that could lead to eye injuries, and good eye care can help reduce the risk of corneal ulcers. For susceptible dogs, special eye drops to moisturize the eyes can be helpful.