• Clarity and brightness
• Equal pupil size
• Absence of discharge or crusting
• Pink (not red) conjunctiva
• A third eyelid that remains hidden when awake

Common Causes of Eye Infections

Infectious Agents

Viral Infections:

• Feline Herpesvirus-1 (FHV-1): The most common cause of conjunctivitis and corneal ulcers.
• Feline Calicivirus: Can cause conjunctivitis alongside oral ulcers.
• Feline Immunodeficiency Virus (FIV): Increases susceptibility to opportunistic infections.
• Feline Leukemia Virus (FeLV): Compromises immune function, leading to secondary issues.

Bacterial Infections:

• Chlamydophila felis: A frequent cause of chronic conjunctivitis.
• Mycoplasma species: Often appears secondary to viral infections.
• Staphylococcus and Streptococcus: Common secondary bacterial invaders.

Fungal Infections:

• Rare but serious.
• Often associated with systemic fungal diseases.
• Require specialized, long-term treatment.

Non-Infectious Causes

• Trauma: Scratches, foreign bodies, or chemical irritants.
• Allergies: Environmental allergens triggering allergic conjunctivitis.
• Structural Abnormalities: Entropion (inward-rolling eyelids), eyelid masses, or blocked tear ducts.
• Systemic Diseases: Hypertension, diabetes, or autoimmune conditions that manifest in the eyes.

Types of Feline Eye Infections and Conditions

1. Conjunctivitis (Pink Eye)

What it is: Inflammation of the conjunctiva, the most common eye condition in cats.

Symptoms:

• Redness of the eye membranes
• Excessive squinting or blinking
• Clear, yellow, or green discharge
• Swollen eyelids
• Frequent pawing at the eye

Causes:

• Viral (herpesvirus is most common)
• Bacterial
• Allergic reactions
• Exposure to irritants

Treatment:

• Antibiotic eye drops or ointment ($15 - $40)
• Antiviral medications for herpesvirus ($25 - $60)
• Supportive care and addressing the underlying cause

Estimated Cost: $100 - $300 for uncomplicated cases.

2. Corneal Ulcers

What it is: Open sores on the cornea that can threaten vision if severe.

Types:

• Simple Ulcers: Surface-level, typically healing within 3-5 days.
• Complex Ulcers: Deeper and may require surgical intervention.
• Indolent Ulcers: Chronic, slow-healing erosions common in older cats.
• Descemetoceles: The deepest ulcers, risking eye rupture.

Symptoms:

• Severe squinting and pain
• Excessive tearing
• Cloudiness or a visible defect on the cornea
• Pawing at the eye
• Light sensitivity

Causes:

• Trauma (fight wounds, foreign bodies)
• Herpesvirus infection
• Dry eye (keratoconjunctivitis sicca)
• Entropion (rolled-in eyelid)

Treatment:

• Topical antibiotics ($15 - $40)
• Atropine for pain management ($15 - $30)
• Antiviral medications ($25 - $60)
• Elizabethan collar to prevent rubbing ($10 - $25)
• Surgery for deep ulcers ($800 - $2,500)

Estimated Cost: $150 - $500 for simple cases; $1,000 - $3,000+ for surgical cases.

3. Keratitis

What it is: Inflammation of the cornea.

Types:

• Ulcerative: Accompanied by a corneal ulcer.
• Non-ulcerative: Without an ulcer, often immune-mediated.
• Eosinophilic: Associated with allergic or immune conditions.
• Herpetic: Caused by FHV-1.

Symptoms:

• Cloudy or hazy cornea
• Blood vessel growth into the cornea
• Visible discomfort
• Excessive tearing

Treatment:

• Important: Corticosteroids are used only for non-ulcerative cases and are dangerous if an ulcer is present.
• Antiviral medications
• Cyclosporine for immune-mediated cases

Estimated Cost: $200 - $600, depending on treatment duration.

4. Uveitis (Iritis)

What it is: Inflammation of the uveal tract (iris and ciliary body), a serious condition that can lead to blindness.

Symptoms:

• Deep red eye (not just surface redness)
• Cloudy appearance
• A small, constricted pupil
• Sensitivity to light
• Elevated third eyelid

Causes:

• Infectious (FIP, toxoplasmosis, FIV, FeLV, fungal)
• Trauma
• Immune-mediated disorders
• Cancer (e.g., lymphoma)
• Idiopathic (unknown cause)

Treatment:

• Corticosteroids ($20 - $50)
• Atropine ($15 - $30)
• Treatment of the underlying cause
• Systemic medications if needed

Estimated Cost: $300 - $1,000+

Critical Note: Uveitis always indicates a serious underlying disease and requires a thorough diagnostic workup.

5. Blepharitis

What it is: Inflammation of the eyelids.

Symptoms:

• Swollen, reddened eyelids
• Itching or discomfort
• Crusting at the eyelid margins
• Hair loss around the eyes

Causes:

• Bacterial infection
• Demodex mites
• Allergies
• Autoimmune conditions

Treatment:

• Topical antibiotics ($15 - $35)
• Warm compresses
• Addressing the underlying cause

Estimated Cost: $100 - $300

6. Dacryocystitis

What it is: Infection or inflammation of the tear drainage system (nasolacrimal duct).

Symptoms:

• Constant tearing (epiphora)
• Mucoid discharge
• Swelling at the inner corner of the eye
• Pain when the area is touched

Causes:

• Blockage from infection, debris, or congenital abnormalities
• Spread of an upper respiratory infection

Treatment:

• Antibiotics ($20 - $50)
• Flushing of the tear ducts ($100 - $300)
• Surgery for persistent obstructions ($500 - $1,500)

Estimated Cost: $200 - $1,500

Recognizing Symptoms: A Triage Guide

Mild Symptoms (Schedule a Veterinary Appointment)

• Slight eye discharge
• Mild redness
• Occasional squinting
• Slight third eyelid elevation

Moderate Symptoms (Schedule Within 24-48 Hours)

• Persistent discharge (clear or colored)
• Continued squinting
• Noticeable redness
• Rubbing or pawing at the eye
• Cloudy appearance

Severe Symptoms (Seek Emergency Care Immediately)

• Sudden vision loss or bumping into objects
• Signs of severe pain (vocalizing, hiding)
• Obvious eye injury or trauma
• Protruding eyeball
• Severe cloudiness or color change
• Bleeding from the eye
• Sudden difference in pupil size

The Veterinary Diagnostic Process

Standard Examination

• Visual Inspection: Assessment of all eye structures.
• Fluorescein Stain: Detects corneal ulcers by highlighting damaged areas.
• Schirmer Tear Test: Measures tear production.
• Tonometry: Measures intraocular pressure.
• Eyelid and Surrounding Structure Exam.

Additional Testing (If Indicated)

• Conjunctival Scrapings for Cytology: $30 - $60
• Bacterial Culture and Sensitivity: $100 - $200
• PCR Testing for Herpesvirus: $100 - $250
• Blood Work for Systemic Disease: $100 - $300
• Imaging (X-rays, Ultrasound): $200 - $500
• Referral to a Veterinary Ophthalmologist: $200 - $400 consultation fee

Modern Treatment Approaches

Topical Medications

• Antibiotic Ointments/Drops: Erythromycin, Terramycin, triple antibiotics. Cost: $15 - $40.
• Antiviral Medications: Idoxuridine, Trifluridine, compounded Cidofovir. Cost: $25 - $75.
• Anti-Inflammatories: Corticosteroids (contraindicated with ulcers), NSAIDs. Cost: $15 - $40.
• Lubricants: Artificial tears, gels for dry eye. Cost: $10 - $25.

Systemic Medications

• Oral Antibiotics: For systemic or severe infections like chlamydia. Cost: $25 - $60.
• Antivirals: Famciclovir for managing herpesvirus. Cost: $50 - $150.
• L-Lysine: An amino acid supplement that may reduce herpesvirus recurrence. Cost: $10 - $25 monthly.
• Cyclosporine: For immune-mediated conditions like dry eye. Cost: $50 - $150 monthly.

Supportive Care

• Elizabethan Collar (E-Collar): Prevents self-trauma. Cost: $10 - $25.
• Warm Compresses: Effective for eyelid conditions like blepharitis.
• Environmental Management: Using humidifiers, maintaining cleanliness. Cost: $20 - $50.

Surgical Interventions

• Corneal Surgery: For deep ulcers or perforations. Cost: $800 - $2,500.
• Entropion Correction: For rolled-in eyelids. Cost: $400 - $1,200.
• Enucleation: Eye removal for untreatable, painful conditions. Cost: $800 - $2,000.
• Nasolacrimal Duct Surgery: For persistent blockages. Cost: $500 - $1,500.

Cost Breakdown for Common Scenarios (2026 Estimates)

Uncomplicated Conjunctivitis

Corneal Ulcer Treatment

Uveitis Workup and Treatment

The Role of Pet Insurance

Most pet insurance plans cover eye infections and conditions, typically reimbursing 70-90% of costs after the deductible is met. Given the potential for high expenses with serious conditions, insurance is a valuable tool for financial peace of mind.

Home Care During Treatment

Administering Eye Medications: A Step-by-Step Guide

1. Wash Hands: Thoroughly before and after.
2. Clean Discharge: Gently wipe away any crust with a warm, damp cloth.
3. Position Your Cat: Tilt the head slightly upward.
4. Apply Medication: Pull down the lower eyelid to create a pocket for drops, or apply ointment along the lid margin. Avoid touching the eye with the applicator.
5. Close and Massage: Gently close the eyelid and massage to distribute the medication.
6. Reward: Offer a treat to create a positive association.

Environmental Management

• Maintain a clean, dust-free living space.
• Use an air purifier if allergies are suspected.
• Ensure the E-collar is worn at all times if prescribed.
• Isolate the cat from others if a contagious infection is diagnosed.

Monitoring Recovery

Watch for positive signs of improvement:

• Decreased or cleared discharge
• Reduced redness and swelling
• Improved comfort (less squinting)
• Return to normal pupil size
• Third eyelid returning to its hidden position

Proactive Prevention Strategies

Vaccination

• Core FVRCP Vaccine: Protects against herpesvirus and calicivirus, major causes of eye infections.
• Schedule: Kittens start a series at 6-8 weeks; adults receive boosters every 1-3 years.
• Cost: $25 - $50 per vaccine.

Environmental & Stress Management

• Stress Reduction: Crucial, as stress triggers herpesvirus flare-ups.
  • Maintain consistent routines.
  • Provide safe hiding places.
  • Consider pheromone diffusers (e.g., Feliway). Cost: $20 - $40 monthly.
• Hygiene:
  • Regularly clean bedding and common areas.
  • Wash hands between handling multiple cats.
  • Use separate food/water bowls for infected cats.

Nutrition & Supplements

• L-Lysine Supplementation: May help manage herpesvirus. Discuss dosage (typically 250-500mg twice daily) and evidence with your vet. Cost: $10 - $25 monthly.
• Quality Diet: Supports overall immune and eye health.
  • Ensure adequate Omega-3 fatty acids and antioxidants (Vitamins C, E).
  • Taurine is essential for feline eye health and is included in all commercial cat foods.

Regular Veterinary Care

• Annual Examinations: Allow for early detection of subtle eye problems.
• Senior Cats (10+): Benefit from biannual check-ups that include eye screening.
• Vigilance: Address any subtle changes in your cat's eyes or behavior promptly.

Breed-Specific Considerations

Brachycephalic Breeds (Persian, Himalayan, Exotic Shorthair)

• Prominent eyes are more prone to injury, dryness, and exposure.
• Tear drainage issues and staining are common.
• Require more frequent eye cleaning and monitoring.
• Have a higher inherent risk of corneal ulcers.

Long-Term Management of Chronic Conditions

Herpesvirus Carriers

Cats infected with FHV-1 remain carriers for life. Management focuses on:

• Expecting and preparing for periodic recurrences.
• Implementing stress reduction as a primary prevention tool.
• Keeping antiviral or supportive medications on hand for early intervention.
• Monitoring for signs of secondary bacterial infections.

Other Chronic Conditions

• Dry Eye (KCS): Requires lifelong application of lubricating drops or cyclosporine.
• Chronic Conjunctivitis: May need intermittent treatment cycles.
• Eosinophilic Keratitis: Often managed with long-term immune-suppressing medications.

When to Seek Emergency Care

Seek immediate veterinary attention if your cat exhibits:

• Sudden vision loss or disorientation.
• Suspected chemical exposure to the eye.
• Any penetrating eye injury.
• Signs of severe pain (hiding, vocalizing, aggression).
• A cloudy eye combined with signs of systemic illness (lethargy, fever).
• A protruding eyeball (proptosis).

Prognosis Overview

• Conjunctivitis: Excellent with proper treatment, though herpesvirus carriers may experience recurrences.
• Corneal Ulcers: Good for simple ulcers; more guarded for deep or indolent ulcers requiring surgery.
• Uveitis: Variable; depends entirely on the underlying cause. Can lead to blindness if untreated.
• Keratitis: Variable; chronic forms often require ongoing, lifelong management.

Conclusion

Eye infections in cats present a spectrum of concerns, from temporary irritations to vision-threatening emergencies. Recognizing the signs, acting promptly with veterinary care, and adhering diligently to treatment plans are the cornerstones of protecting your cat's sight.

While some causes, like feline herpesvirus, result in a lifelong carrier state, effective management through stress reduction, good nutrition, and proactive veterinary care can minimize outbreaks and maintain your cat's comfort and quality of life.

Remember: Eye symptoms should never be ignored. A "red eye" is always a signal for evaluation. With informed care and attention, most cats with eye infections recover fully and enjoy excellent vision throughout their lives.