Cat Eye Infections: Causes, Signs and Treatment

Reviewed by Dr. Ameer Hamza, DVM

Eye problems are among the more common health concerns in cats, and the signs can range from mild ocular discharge to severe, painful conditions that can compromise vision if left untreated. The eye is one of the most sensitive organs and most eye problems in cats warrant prompt veterinary attention rather than a wait-and-see approach. This guide covers the most common causes of feline eye infections, the signs to watch for, what appropriate home care looks like, and when you need to see a vet urgently.

Signs of an Eye Problem in Cats

The signs that indicate an eye problem requiring attention include: discharge from one or both eyes, ranging from watery and clear (more commonly viral or allergic) to thick, sticky, and yellow-green (more commonly bacterial); redness of the conjunctiva (the pink tissue surrounding the eyeball and lining the eyelids); squinting — a cat holding one or both eyes partially or fully closed is in ocular discomfort; pawing or rubbing at the eye or face; cloudiness of the normally transparent cornea; third eyelid protrusion — the pale nictitating membrane visible across the inner corner of the eye; and asymmetry — one eye appearing noticeably different in size, clarity, or position compared to the other. Any of these signs in combination with apparent discomfort or in a kitten is a prompt for veterinary assessment.

Feline Herpesvirus: The Most Common Cause

Feline herpesvirus-1 (FHV-1) is by far the most common cause of ocular disease in cats. The virus is endemic in the cat population — estimates suggest the majority of cats have been exposed, and many carry it as a latent infection that reactivates during stress. Primary infection (typically in kittens) causes 'cat flu' — sneezing, nasal discharge, fever, and conjunctivitis. In kittens, severe FHV-1 eye infection before the eyes fully open can cause scarring and permanent damage. Latent FHV-1 infection reactivates during stress — rehoming, new pets, surgery, illness — producing periodic flares of ocular discharge, conjunctivitis, and sometimes corneal ulceration. Chronic or recurrent eye problems in a cat with a history of upper respiratory infection are very commonly herpesvirus-related.

Bacterial Infection and Chlamydophila

Bacterial conjunctivitis can develop as a primary infection or secondary to viral damage. Chlamydophila felis is a significant bacterial cause of chronic, often bilateral (both eyes) conjunctivitis in cats. It causes persistent ocular discharge, swollen conjunctiva, and is particularly common in multi-cat households and catteries. It responds well to topical and systemic antibiotic treatment. Secondary bacterial infections frequently complicate FHV-1 infection because viral damage to the conjunctival surface creates an ideal environment for bacterial colonisation.

Corneal Ulcers

A corneal ulcer is a break in the epithelial surface of the cornea. It can result from physical injury, foreign bodies, abnormal eyelid conformation (entropion), or viral damage (herpesvirus causes a characteristic dendritic corneal ulcer pattern). Symptoms include significant squinting, tearing, cloudiness of the cornea, and visible discomfort. Corneal ulcers are painful and can progress rapidly — a shallow ulcer can deepen to a descemetocoele (full-thickness ulceration) or frank corneal perforation within days without treatment. They should always be assessed and treated by a vet. Corticosteroid eye drops can worsen corneal ulceration severely and must never be applied to an eye with a suspected ulcer without veterinary assessment.

Home Care for Mild Cases

For very mild, uncomplicated ocular discharge in a cat that is otherwise bright, alert, not squinting, and not showing signs of discomfort, gentle cleaning of the eye area is appropriate while monitoring: gently wipe discharge from the corner of the eye and surrounding fur with a clean gauze pad or soft cloth dampened with cooled boiled water (or sterile saline). Use a fresh piece of gauze for each eye to avoid cross-contamination. Do not use human eye drops, contact lens solution, or any product not specifically formulated for cats. If the discharge is thick, coloured, or the cat is squinting, a vet appointment is the appropriate step rather than home management.

Frequently Asked Questions

What are the signs of a cat eye infection?

Redness, discharge (watery to yellow-green), squinting, pawing at the eye, cloudiness of the cornea, third eyelid protrusion. Bilateral signs more commonly viral; unilateral more commonly bacterial or injury-related.

What causes eye infections in cats?

Feline herpesvirus-1 (most common), Chlamydophila felis, secondary bacterial infections, foreign bodies, physical injury, entropion, and blocked tear ducts.

Can I treat it at home?

Only mild discharge in an otherwise comfortable cat — gently clean with cooled boiled water. Squinting, redness, cloudiness, or significant discharge require veterinary attention. Never delay for eye problems.

Is cat herpesvirus contagious to humans?

No — FHV-1 is species-specific and cannot infect humans or dogs. It is highly contagious between cats, transmitted through direct contact and shared items.

What drops do vets prescribe?

Topical antibiotics for bacterial infection; antiviral drops for FHV-1 corneal ulcers. Corticosteroids are sometimes used for inflammation but are contraindicated with corneal ulcers — always confirm diagnosis before treatment.

For comprehensive cat health guidance, see the complete cat care guide.

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Disclaimer: This article is for educational purposes only. Eye problems in cats can progress rapidly — if in doubt, seek veterinary assessment promptly rather than attempting home treatment.