Feline Herpesvirus (FHV-1): Symptoms, Treatment & Management Guide

What is Feline Herpesvirus?

Feline herpesvirus type 1 (FHV-1), also known as feline viral rhinotracheitis (FVR), is a highly contagious upper respiratory infection in cats. It is one of the most common viral infections in cats and is a major component of feline upper respiratory infection complex (URI). Once infected, cats carry the virus for life.

How FHV-1 Is Transmitted

• Direct contact: Saliva, nasal and ocular discharge
• Aerosol droplets: Sneezing and coughing
• Contaminated objects: Food bowls, bedding, grooming tools
• Mother to kitten: During birth or nursing
• Latent infection: Stress reactivates the virus in carrier cats

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Symptoms

Acute Infection (2-6 days after exposure)

• Sneezing (often frequent and severe)
• Nasal discharge (clear to thick, yellow-green)
• Ocular discharge (clear to thick)
• Conjunctivitis (red, swollen eyes)
• Squinting and eye irritation
• Fever (102.5-105°F)
• Loss of appetite
• Lethargy

Severe Cases

• Corneal ulcers (painful eye lesions)
• Keratitis (corneal inflammation)
• Pneumonia (rare but serious)
• Dehydration (from not eating/drinking)

Chronic/Latent Phase

• No symptoms between flare-ups
• Stress triggers recurrence: New environments, other cats, illness, pregnancy
• Mild symptoms during flare-ups: Sneezing, eye discharge
• Lifelong carrier state

Who Is at Risk?

• Kittens (most susceptible, can be severe)
• Unvaccinated cats
• Multi-cat households and shelters
• Cats under stress (new home, surgery, illness)
• Persian and flat-faced breeds (more susceptible to eye complications)

Diagnosis & Costs

Diagnostic Tests

• Physical exam: $50-100
• PCR testing (ocular/nasal swabs): $150-300
• Fluorescein stain (corneal ulcers): $20-50
• Schirmer tear test (dry eye assessment): $20-40
• CBC: $80-150

Total Diagnostic Cost: $100-500

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Treatment

Mild Cases (Outpatient)

• L-lysine supplement (250-500mg twice daily): $15-30/month
• Antiviral eye drops (idoxuridine, cidofovir): $40-80/bottle
• Antibiotic eye ointment (Terramycin): $15-30
• Nasal decongestant: $15-30
• Humidifier therapy: Free

Severe Cases (Hospitalization)

• IV fluids for dehydration: $100-200/day
• Antiviral medications (famciclovir): $40-80/day
• Antibiotics for secondary infections: $40-100/day
• Eye surgery (for severe corneal damage): $500-2,000
• Nasogastric tube feeding (if not eating): $50-100/day

Total Treatment Cost

• Mild case: $50-$300
• Moderate case: $300-$800
• Severe case: $800-$3,000+

Prevention

Vaccination (Core Vaccine)

• FVRCP vaccine includes FHV-1 component
• Kitten schedule: 6-8, 10-12, and 14-16 weeks
• Adult boosters: Every 3 years
• Cost: $20-40 per dose
• Reduces severity but does not prevent infection entirely

Management

• Vaccinate before exposure (kittens and new cats)
• Isolate infected cats for 3-4 weeks
• Reduce stress in multi-cat households
• Good ventilation and sanitation
• L-lysine supplementation for known carriers

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Managing Chronic Carriers

Cats that carry FHV-1 for life need ongoing management:

• L-lysine daily: Reduces flare-up frequency
• Stress reduction: Consistent routine, minimal changes
• Prompt treatment of flare-ups
• Regular eye exams for chronic conjunctivitis
• Good nutrition to support immune function

Prognosis

• Adult cats: Usually recover in 7-14 days
• Kittens: Higher risk of severe disease and death
• Chronic carriers: Manageable with good care
• Permanent eye damage: Possible in severe cases

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Related: feline-leukemia, fiv-feline-immunodeficiency-virus, respiratory-infections