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Non-ulcerative keratitis (inflammation of the cornea of the eye) in cats

Occurrence: common
Location of illness: Head/Neck

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

When to visit the vet?

Non-urgent see a veterinarian within 2–3 days

If the condition worsens / symptoms persist, consult a veterinarian.

Definition

Non-ulcerative keratitis, also known as corneal inflammation, is an inflammatory condition of the cornea in cats that is not associated with the formation of ulcers.

The most important facts at a glance

Non-ulcerative keratitis is a corneal inflammation in cats that can be triggered by various factors such as 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. infections, especially felineFeline refers to anything related to cats. The term is used to describe diseases, behaviors, or anatomical aspects that are specific to cats. herpesvirus-1 (FHV-1), as well as bacterial infections, allergies, and environmental irritants. This inflammation manifests through symptoms such as swollen, light gray cornea, blood vessel formation, and pigment deposition. 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. requires a thorough examination by the veterinarian, who rules out corneal ulcers using fluorescein stainingFluorescein staining is a diagnostic technique that uses fluorescein, a fluorescent dye, to make tissues, cells, or microbiological samples visible under a microscope, especially in ophthalmology to detect damage to the cornea. and identifies the causes through further tests.

Treatment depends on the cause: antiviral medications for 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. infections, anti-inflammatory agents for non-infectious causes. Ocular surfaces must be kept moist, and in some cases, surgical intervention is necessary. The prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. depends on the cause; with early 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., it is usually good, but recurrentRecurrent refers to a disease that repeatedly returns or worsens after a temporary remission or improvement. episodes can occur with chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. infections. PreventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. includes regular veterinary examinations, a clean environment, and protecting the cat from injuries.

Research focuses on the role of the 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., microbial flora, and new treatment methods to better understand the disease and improve the quality of life for affected cats. The development of non-invasive diagnostic methods such as optical coherence tomography (OCT) could increase diagnostic accuracy and optimize treatment.

Causes

The cornea is the transparent, outer layer of the eye that serves as a protective barrier and light-refracting element. In cats, the cornea is a sensitive structure that can respond to various stimuli. Inflammation of the cornea without ulcerationAn ulceration is an open wound or sore, typically on the skin or mucous membranes, characterized by the loss of surface tissue. Ulcerations in dogs and cats can be caused by infections, chronic inflammatory conditions, or cancer. can be triggered by a variety of factors, which can be both infectiousInfectious describes the ability of a pathogen to be transmitted from one individual to another and trigger an infection. It also refers to diseases caused by such pathogens. and non-infectious in nature.

One of the most common causes of non-ulcerative keratitis in cats is 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. infections, especially from felineFeline refers to anything related to cats. The term is used to describe diseases, behaviors, or anatomical aspects that are specific to cats. herpesvirus-1 (FHV-1). These viruses can directly attack the cornea or 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 immune responseAn immune response is the immune system's reaction to foreign substances (antigens), such as microorganisms or proteins. It involves a series of processes aimed at recognizing, fighting, and eliminating these antigens. that leads to inflammation. In addition to 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. causes, bacterial infections can also play a role, although these often occur secondary to existing damage.

Non-infectious causes include allergic reactions, environmental irritants such as smoke or dust, and mechanical irritation from foreign bodies or eyelash abnormalities. In addition, systemic diseases such as 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. can contribute to the development of non-ulcerative keratitis.

Symptoms

Very common symptoms:

Common symptoms:

The symptoms of non-ulcerative keratitis in cats are often subtle and can be easily overlooked. They typically include increased tear production, which is referred to as epiphora. This can lead to constant moisture around the eye, which is often perceived by owners as a watery eye.

Another common symptom is redness and Swelling of the conjunctiva, which is known as conjunctivitis. This inflammation can lead to a reddened and irritated appearance of the eye. In addition, the cornea itself may appear cloudy or milky, indicating the inflammatory changes within the tissue.

Cats with non-ulcerative keratitis may also show signs of discomfort, such as frequent blinking or squinting of the affected eye. In some cases, there may be reduced vision if the inflammation is severe enough to impair the light transmission of the cornea.

Diagnosis

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. of non-ulcerative keratitis requires a careful clinical examination by a veterinarian. The veterinarian will first take a comprehensive medical historyThe medical history is the systematic collection of a patient's medical history through questioning. It includes information about previous illnesses, treatments, allergies, and lifestyle habits. to rule out possible predisposing factors or underlying diseases. A thorough examination of the eye with special instruments, such as a slit-lamp microscope, can help visualize the changes in the cornea.

An important component of 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. is the exclusion of corneal ulcers, which can be detected by fluorescein stainingFluorescein staining is a diagnostic technique that uses fluorescein, a fluorescent dye, to make tissues, cells, or microbiological samples visible under a microscope, especially in ophthalmology to detect damage to the cornea. of the cornea. This special stain binds to damaged areas on the cornea, which is not the case with non-ulcerative keratitis.

Additional diagnostic tests may include taking swabs from the conjunctiva for microbiological examination to identify possible infectiousInfectious describes the ability of a pathogen to be transmitted from one individual to another and trigger an infection. It also refers to diseases caused by such pathogens. agents. In some cases, a serological examination or a polymerase chain reaction test (PCR) can be performed to confirm 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. infections such as FHV-1.

Therapy

The treatment of non-ulcerative keratitis depends on the underlying cause. In the case of 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. infections, the use of antiviral drugs may be necessary to inhibit virusA virus is a microscopic infectious particle that cannot reproduce on its own and must infect a host cell to produce new virus particles. Viruses can cause a variety of diseases in humans, animals, and plants. replication. These drugs can be administered in the form of eye drops or systemically, depending on the severity of the disease.

For non-infectious causes, the treatment is primarily symptomatic and includes the use of anti-inflammatory drugsAnti-inflammatory drugs are medications that reduce inflammation. They can be divided into nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids and are used in dogs and cats to reduce Inflammatory conditions and Pain. to reduce inflammation. Corticosteroid eye drops can be effective, but should be used with caution, especially if there is a possibility of a co-existing 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..

In all cases, it is important to keep the eye surface moist and avoid further irritation. Artificial tears or eye-moisturizing gels can be used to support corneal hydration. In some cases, surgical intervention may be necessary, especially if anatomical abnormalities such as entropion eyelids are the cause of the inflammation.

Prognosis and follow-up care

The prognosis for cats with non-ulcerative keratitis varies depending on the cause and severity of the disease. With early 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 appropriate treatment, the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. is generally good, and many cats recover completely or experience a significant improvement in their symptoms.

However, recurrentRecurrent refers to a disease that repeatedly returns or worsens after a temporary remission or improvement. episodes of keratitis can occur in cats with chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. 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. infections such as FHV-1. In such cases, a long-term management strategy may be required to minimize future outbreaks and maintain the cat’s quality of life.

In non-infectious causes that are successfully treated, the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. is also positive, provided that the underlying cause is effectively resolved and future irritation is avoided.

Prevention

To minimize the risk of non-ulcerative keratitis in cats, it is important to perform regular preventive check-ups with the vet. These examinations help to detect & treat potential problems early. A healthy diet rich in vitamins and nutrients supports the cat’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. and can help keep the eyes healthy.

It is also advisable to keep your cat’s living environment clean and free of dust or other irritants that could irritate the eyes. Regularly cleaning the sleeping areas & avoiding smoke or aggressive chemicals in the environment are also useful. Make sure that your cat does not rub its head too often, as this can put additional strain on the eyes.

Another important measure is to protect the cat from injuries. This includes keeping them in a safe environment where the risk of scratches or mechanical injuries is low. If your cat suffers from an underlying condition that increases the risk of keratitis, this condition should be treated accordingly. When in doubt, an early consultation with the vet is always advisable to reduce the risk of non-ulcerative keratitis.

Outlook on current research

Research on non-ulcerative keratitis in cats is a growing field, as this form of corneal inflammation has received less attention than other eye diseases. Scientists and veterinarians are working to better understand the exact causes and develop more effective treatment strategies. Traditionally, non-ulcerative keratitis was thought to be less severe than ulcerativeUlcerative refers to the condition or process that leads to the formation of ulcers. Ulcers are open Wounds or Lesions that can form on the skin or mucous membranes, are painful, and often heal slowly. forms, but recent studies suggest that this form can also lead to significant vision problems if not treated appropriately.

A significant area of research focuses on the role of the 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. in the development and progressionProgression refers to the advancement or worsening of a disease over time. It describes an increase in the severity or extent of the disease symptoms. of non-ulcerative keratitis. It is believed that the inflammation can be triggered by an immune-mediated reaction to various environmental factors or infectiousInfectious describes the ability of a pathogen to be transmitted from one individual to another and trigger an infection. It also refers to diseases caused by such pathogens. agents. Studies are investigating how genetic predispositions and environmental stressors, such as air pollution or allergens, can contribute to the development of this disease.

Another interesting area of research is the study of the microbial flora of the ocular surface in cats. Researchers are trying to determine whether changes in the normal bacterial colonization of the ocular surface are associated with the development of non-ulcerative keratitis. 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 certain bacterial strains, which are normally harmless, can enhance the inflammatory response under certain conditions.

In terms of treatment, intensive work is being carried out to develop new drug formulations that have anti-inflammatory effects without damaging the corneal cells. These studies aim to avoid the side effects of traditional treatments such as corticosteroidsCorticosteroids are a class of steroid hormones that occur naturally in the body and can also be produced synthetically. They have anti-inflammatory and immunosuppressive properties and are used in veterinary medicine to treat a variety of conditions.. In addition, the use of immunomodulatoryImmunomodulatory describes the ability of a substance to modify the reaction of the immune system. Immunomodulatory drugs can either stimulate the immune system to fight infections more effectively or suppress it to prevent overreactions. agents and natural remedies, such as honey or herbal extracts, is being investigated as potentially effective alternatives.

The development of non-invasive diagnostic methods is another important research focus. Advances in imaging technology, such as high-resolution optical coherence tomography (OCT), offer promising opportunities to analyze the structure of the cornea in detail and increase diagnostic accuracy. This could allow veterinarians to detect the disease earlier and adjust the 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. accordingly.

In summary, research on non-ulcerative keratitis in cats is advancing in many ways. These efforts promise to significantly improve both the understanding of the disease and the treatment options, which could ultimately improve the quality of life of affected cats.

Frequently asked questions (FAQs)

What is non-ulcerative keratitis in cats? Non-ulcerative keratitis is a form of corneal inflammation in which the cat’s cornea is affected without ulcers or open wounds. It can be triggered by various factors such as infections, irritations or immune-mediated reactions.
What symptoms do cats with non-ulcerative keratitis show? Typical symptoms include redness, tearing, light sensitivity, and a cloudy or milky discoloration of the cornea. Cats may also show Pain or discomfort by frequently rubbing or blinking their eyes.
How is non-ulcerative keratitis diagnosed in cats? 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. is made by a thorough examination of the eye by a veterinarian. This may include a slit-lamp examination and further diagnostic tests to rule out other causes of eye problems.
What treatment options are available for non-ulcerative keratitis? The treatment depends on the cause and may include the use of anti-inflammatory eye drops, antibiotics, or immunomodulatoryImmunomodulatory describes the ability of a substance to modify the reaction of the immune system. Immunomodulatory drugs can either stimulate the immune system to fight infections more effectively or suppress it to prevent overreactions. drugs. An accurate 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. is crucial to select the appropriate 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 home remedies help with treatment? While some natural remedies such as eye drops with physiological saline solution can help relieve symptoms, all treatments should be coordinated with a veterinarian to ensure that they are safe and effective.
Is non-ulcerative keratitis contagiousContagious means infectious. Diseases that can easily be transmitted from one animal to another or from animals to humans are referred to as contagious.? No, the non-ulcerative form of keratitis is usually not contagiousContagious means infectious. Diseases that can easily be transmitted from one animal to another or from animals to humans are referred to as contagious., as it is often caused by non-infectious causes such as allergies or autoimmune reactions.
Can all cats develop non-ulcerative keratitis? Yes, generally, cats of all breeds and age groups can be affected. However, certain breeds or cats with a genetic 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. may be more susceptible.
How can I reduce the risk of non-ulcerative keratitis in my cat? Regular eye care, avoiding irritants, and timely treatment of allergies or infections can help reduce the risk. Regular vet visits for early detection of problems are also important.
Can non-ulcerative keratitis lead to vision loss? In severe cases or if the disease remains untreated, scar tissue formation or other complications can occur, which may impair vision. Early 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 are crucial to prevent this.
How long does it take for a cat to recover from non-ulcerative keratitis? Recovery time varies depending on the severity of the disease and the chosen 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.. With proper 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., symptoms can improve within a few weeks, but complete healing may take longer.

Frequently asked questions (FAQs)

1. What is non-ulcerative keratitis in cats?

Non-ulcerative keratitis is a form of corneal inflammation in which the cat's cornea is affected without ulcers or open wounds. It can be triggered by various factors such as infections, irritations or immune-mediated reactions.

2. What symptoms do cats with non-ulcerative keratitis show?

Typical symptoms include redness, tearing, light sensitivity, and a cloudy or milky discoloration of the cornea. Cats may also show Pain or discomfort by frequently rubbing or blinking their eyes.

3. How is non-ulcerative keratitis diagnosed in cats?

The diagnosis is made by a thorough examination of the eye by a veterinarian. This may include a slit-lamp examination and further diagnostic tests to rule out other causes of eye problems.

4. What treatment options are available for non-ulcerative keratitis?

The treatment depends on the cause and may include the use of anti-inflammatory eye drops, antibiotics, or immunomodulatory drugs. An accurate diagnosis is crucial to select the appropriate therapy.

5. Can home remedies help with treatment?

While some natural remedies such as eye drops with physiological saline solution can help relieve symptoms, all treatments should be coordinated with a veterinarian to ensure that they are safe and effective.

6. Is non-ulcerative keratitis contagious?

No, the non-ulcerative form of keratitis is usually not contagious, as it is often caused by non-infectious causes such as allergies or autoimmune reactions.

7. Can all cats develop non-ulcerative keratitis?

Yes, generally, cats of all breeds and age groups can be affected. However, certain breeds or cats with a genetic predisposition may be more susceptible.

8. How can I reduce the risk of non-ulcerative keratitis in my cat?

Regular eye care, avoiding irritants, and timely treatment of allergies or infections can help reduce the risk. Regular vet visits for early detection of problems are also important.

9. Can non-ulcerative keratitis lead to vision loss?

In severe cases or if the disease remains untreated, scar tissue formation or other complications can occur, which may impair vision. Early diagnosis and treatment are crucial to prevent this.

10. How long does it take for a cat to recover from non-ulcerative keratitis?

Recovery time varies depending on the severity of the disease and the chosen therapy. With proper therapy, symptoms can improve within a few weeks, but complete healing may take longer.