A cat eye infection — most commonly feline conjunctivitis — occurs when the membrane lining the eyelid becomes inflamed due to bacteria, viruses (especially herpesvirus), or other irritants. Cat eye infections are among the most common health issues in cats, especially in kittens and multi-cat households, and early recognition of symptoms like discharge, squinting, and redness is key to fast recovery.
This guide is for informational purposes. Always consult your veterinarian for diagnosis and appropriate treatment of any eye condition in your cat.
Common Causes of Cat Eye Infections
Unlike dogs, cats are far more frequently affected by viral causes of eye infection — particularly feline herpesvirus type 1 (FHV-1), which is estimated to infect up to 80% of cats at some point in their lives. The most common causes of cat eye infections include:
- Feline Herpesvirus (FHV-1): The leading cause of conjunctivitis in cats. Once infected, cats carry the virus for life and may have flare-ups during times of stress or illness. Often associated with upper respiratory infections.
- Chlamydophila felis (bacteria): Causes persistent conjunctivitis, often in one eye initially before spreading to both. Common in multi-cat environments.
- Mycoplasma: A bacterial organism that can cause conjunctivitis, often alongside respiratory symptoms.
- Feline calicivirus: A viral upper respiratory infection that can cause mild conjunctivitis alongside mouth ulcers and limping.
- Allergies and irritants: Dust, smoke, perfumes, and household cleaning products can cause mild eye irritation and discharge.
- Foreign bodies: Grass seeds, dust, or debris can become trapped under the eyelid.
- Structural issues: Flat-faced (brachycephalic) cats like Persians and Exotic Shorthairs often have chronic eye discharge due to shallow eye sockets and poor tear drainage.
Symptoms of a Cat Eye Infection
| Symptom | Possible Cause | Action Required |
|---|---|---|
| Clear watery discharge | Mild irritation, early viral infection | Monitor closely |
| Yellow/green thick discharge | Bacterial infection | Vet within 24 hrs |
| Squinting or keeping eye closed | Pain, corneal ulcer, foreign body | Vet same day |
| Red, inflamed eye membranes | Conjunctivitis | Vet within 24 hrs |
| Cloudiness or hazy appearance | Corneal ulcer, keratitis | Emergency vet |
| Third eyelid visible | Illness, injury, dehydration | Vet within 24 hrs |
| Brown facial staining | Chronic epiphora (tear overflow) | Vet check-up |
Based on veterinary ophthalmology guidelines, 2025.
See our related guide on cat eye care for tips on keeping your cat’s eyes clean between vet visits.
Types of Feline Eye Conditions
Not all cat eye problems are simple conjunctivitis. Understanding the different types helps owners communicate effectively with their vet:
- Conjunctivitis: Inflammation of the conjunctiva — the most common feline eye condition. Can be unilateral (one eye) or bilateral (both eyes). Herpesvirus conjunctivitis often starts in one eye.
- Keratitis: Inflammation of the cornea, often caused by herpesvirus. Can cause corneal cloudiness and, if untreated, scarring.
- Corneal Sequestrum: A unique feline condition where a dark plaque forms on the cornea, more common in Persians and Siamese. Requires surgical removal.
- Uveitis: Inflammation of the eye’s inner structures. Often indicates a systemic disease such as FIV, FeLV, toxoplasmosis, or feline leukemia.
- Epiphora (Tear Overflow): Excessive tearing causing rust-colored staining on the face. Common in flat-faced breeds due to poor tear duct drainage.
Treatment Options for Cat Eye Infections
Treatment varies depending on the underlying cause identified by your veterinarian:
- Antiviral medications: For FHV-1, veterinarians may prescribe topical antiviral eye drops (idoxuridine, cidofovir) or oral famciclovir. L-lysine supplementation was historically recommended but current evidence doesn’t strongly support it for all cats.
- Antibiotic eye drops: For bacterial infections (Chlamydophila, Mycoplasma). Topical tetracycline or azithromycin ophthalmic preparations are commonly used.
- Anti-inflammatory drops: Corticosteroids may reduce inflammation but must NOT be used if a corneal ulcer is present or suspected.
- Artificial tears: Help flush debris and soothe irritation for mild cases.
- Stress management: For FHV-1 cats, reducing stress (through environmental enrichment, Feliway diffusers, routine) can reduce recurrence frequency.
- Surgery: For corneal sequestrum, entropion (inward-rolling eyelid), or blocked nasolacrimal ducts.
Find a trusted veterinary clinic near you on HeiBob for an accurate diagnosis and treatment plan tailored to your cat.
Home Care and Prevention
While veterinary treatment is essential for infections, these home care practices support healing and help prevent recurrence:
- Gently wipe discharge: Use a clean, damp cotton ball to wipe away discharge from the inner corner of the eye outward. Use a separate cotton ball for each eye to avoid spreading infection.
- Keep the environment clean: Wash bedding regularly and ventilate your home well — strong cleaning product fumes can irritate feline eyes.
- Reduce stress: Stress triggers FHV-1 flare-ups. Provide enrichment, stable routines, and appropriate space — especially important in multi-cat households.
- Vaccinate regularly: Core feline vaccines (FVRCP) include protection against herpesvirus and calicivirus. While they don’t prevent infection completely, they reduce severity.
- Isolate infected cats: If you have multiple cats, keep the infected cat separated until fully recovered to prevent spread of bacterial or viral infections.
- Nutrition support: Good nutrition supports immune function. Review our cat nutrition guides for general health support.
Frequently Asked Questions About Cat Eye Infections
What does a cat eye infection look like?
A cat eye infection typically presents as redness of the conjunctiva (the pink lining around the eye), discharge ranging from clear and watery to thick yellow-green, squinting or closing one or both eyes, swollen eyelids, and the third eyelid may be partially visible. Flat-faced cats often have chronic mild discharge that may look like brown or rust-colored staining around the eye corners.
What causes cat eye infections?
The most common cause of cat eye infections is feline herpesvirus (FHV-1), which affects the majority of cats at some point. Other causes include Chlamydophila felis bacteria, Mycoplasma, feline calicivirus, allergies, foreign bodies, and structural issues in brachycephalic (flat-faced) breeds. Kittens and immunocompromised cats are most susceptible to infectious causes.
How is a cat eye infection treated?
Treatment depends on the cause. Viral infections (FHV-1) may be treated with antiviral eye drops or oral antiviral medications. Bacterial infections are treated with antibiotic eye drops or ointments. Anti-inflammatory drops may be prescribed to reduce swelling (though not if a corneal ulcer is present). Your vet will examine the eye and may run diagnostic tests before prescribing treatment. Most infections improve within 7–14 days of appropriate treatment.
Can cat eye infections spread to other cats or humans?
Yes, bacterial causes (Chlamydophila, Mycoplasma) and viral causes (FHV-1, calicivirus) of cat conjunctivitis can spread between cats through direct contact, shared food/water bowls, or shared litter boxes. Keep infected cats separated from other household cats. The risk of transmission to humans is extremely low — feline herpesvirus and Chlamydophila felis are species-specific and do not infect humans. Basic hand hygiene after handling an infected cat is still recommended.
How can I prevent cat eye infections?
Key prevention strategies include keeping vaccinations current (FVRCP vaccine covers herpesvirus and calicivirus), reducing stress in your cat’s environment (particularly important for FHV-1 carriers), maintaining good hygiene in multi-cat households, regular grooming of long-haired and flat-faced breeds, and scheduling annual veterinary wellness exams. Cats who have had one episode of conjunctivitis are at higher risk for recurrence and benefit from closer monitoring.
Don’t let a cat eye infection go untreated — early care means faster recovery and less discomfort for your cat. Find a veterinary clinic near you on HeiBob for expert diagnosis and treatment.