Feline Corneal Ulcer

Overview

A defect or erosion in the cornea (the clear front surface of the eye), ranging from a superficial, minor scratch-like injury to a deep ulcer threatening the structural integrity of the eye itself. In cats specifically, Feline Herpesvirus infection is a particularly common underlying or contributing cause, distinct from the more purely traumatic ulcers seen commonly in some other species.

Symptoms

• Squinting (moderate, very common)
• Excessive tearing/discharge (moderate, very common)
• Pawing at the eye (moderate, common)
• Visible cloudiness of the eye (moderate, common)

Causes

Trauma (a scratch from another cat, plant material, or environmental contact) is a common direct cause; Feline Herpesvirus infection is a particularly notable underlying or contributing cause in cats, sometimes producing a characteristic branching ulcer pattern; other causes include eyelid abnormalities causing chronic irritation, and reduced tear production. A defect in the corneal surface, ulcers can result from trauma (a scratch from another cat or environmental hazard), herpesvirus infection (a particularly common cause in cats specifically), or as a complication of another underlying eye condition affecting normal tear film or eyelid function.

Risk Factors

Outdoor access (increasing trauma risk from plant material or cat fights), a history of Feline Herpesvirus infection (which can cause recurrent corneal involvement even long after the initial infection, as the virus can remain latent and reactivate — see the Feline Upper Respiratory Infection Complex entry), and any eyelid conformation abnormality causing chronic corneal irritation.

Transmission

Not directly transmitted, though if herpesvirus is the underlying cause, that specific virus is itself contagious between cats (see the Feline Upper Respiratory Infection Complex entry).

Incubation Period

Not applicable in the traditional sense; onset following trauma is immediate, while herpesvirus-related ulcers can develop when the latent virus reactivates, sometimes triggered by stress.

Disease Stages & Progression

A superficial ulcer can heal within days with appropriate treatment; without treatment, or if infection develops, an ulcer can progressively deepen, threatening the structural integrity of the eye — this progression risk is why any suspected corneal ulcer needs prompt veterinary evaluation rather than a wait-and-see approach.

Early Warning Signs

Squinting, excessive blinking, tearing/discharge, pawing at or rubbing the eye, and visible cloudiness or a change in the eye's normal clear, glossy appearance.

Advanced Symptoms

Significant pain, a visibly deep or large ulcer, the cornea appearing to bulge (suggesting a very deep, dangerous ulcer at risk of rupture), and discharge that becomes thicker or discolored suggesting secondary infection.

Diagnostic Methods

Fluorescein stain, a special dye applied to the eye that highlights areas where the corneal surface is disrupted, is the standard diagnostic test, making an ulcer clearly visible under blue light even when it might not be obvious to the naked eye.

Veterinary Examination Process

Careful eye examination including fluorescein staining to identify and assess the size/depth of any ulcer, and evaluation of the eyelids and tear production for any contributing anatomical or functional issue.

Recommended Lab Tests

Not typically needed for a straightforward case; a swab for herpesvirus testing may be considered in cases with a suspicious pattern or recurrent history.

Diagnostic Imaging

Not primarily used; direct examination with special staining (see diagnostic methods) is the key diagnostic approach for the eye itself.

Blood Test Indicators

Not specific to corneal ulcers; not routinely needed for diagnosis of an isolated ulcer.

Biopsy / Histopathology

Not applicable to standard corneal ulcer diagnosis and treatment.

Differential Diagnoses

Conjunctivitis without corneal involvement, uveitis, and other causes of eye discomfort — fluorescein staining specifically distinguishes a true corneal ulcer from these other conditions.

Home Monitoring Guidance

Not appropriate as a substitute for prompt veterinary evaluation of any suspected eye injury or new eye discomfort — corneal ulcers can progress quickly, and what looks minor can conceal a deeper problem without professional examination.

Veterinary Treatment Options

Topical antibiotic treatment addresses or prevents secondary bacterial infection while the ulcer heals; antiviral treatment is added if herpesvirus is the suspected cause. An Elizabethan collar prevents the cat from further traumatizing the eye through rubbing during healing. Deep or non-healing ulcers may need surgical intervention to protect the eye's structural integrity. Treatment depends on depth and cause — superficial ulcers often heal with appropriate antibiotic drops and addressing any underlying cause (like herpesvirus, which may need antiviral treatment too); deeper ulcers may need more intensive treatment including, for the most severe cases, surgical support to prevent or address perforation.

Surgery Requirements

Deep ulcers, or those not healing with medical treatment, may require surgical procedures to protect and support the healing cornea, ranging from relatively minor procedures to more involved surgery for very deep or complicated ulcers.

Recovery Timeline

Superficial ulcers often heal within a week with appropriate treatment; deeper ulcers take longer and require closer monitoring to confirm appropriate healing progress rather than worsening.

Possible Complications

Corneal rupture (a serious emergency) if a deep ulcer isn't addressed, permanent corneal scarring affecting vision in the affected area, and secondary infection complicating and delaying healing.

Long-Term Management

Cats with recurrent herpesvirus-related corneal ulcers may benefit from stress reduction (given the virus's stress-triggered reactivation pattern) and, in some cases, longer-term antiviral or immune-supportive management under veterinary guidance.

Prevention

Managing environmental stress in herpesvirus-positive cats may reduce reactivation frequency; addressing any eyelid conformation issue contributing to chronic irritation; and reducing outdoor trauma risk through supervised or indoor-focused living.

Vaccination Availability

The core FVRCP vaccine, which includes protection against Feline Herpesvirus, reduces the severity of herpesvirus infection generally, which can indirectly reduce herpesvirus-related corneal ulcer risk, though it doesn't prevent all herpesvirus-related eye issues in an already-infected cat.

Prognosis

Good for superficial ulcers with prompt appropriate treatment; more guarded for deep ulcers or those complicated by infection, where risk to the eye's structural integrity is real without timely, appropriate care.

References

American College of Veterinary Ophthalmologists (ACVO); American Association of Feline Practitioners (AAFP).

Medications Used

• Topical antibiotic eye medication
• Topical antiviral medication, if herpesvirus is suspected
• Pain management
• Specifically AVOID topical corticosteroids in an eye with an active ulcer, since these can worsen an ulcer and delay healing — this is an important treatment distinction from some other eye conditions

Estimated Treatment Cost by Country

Frequently Asked Questions