Feline Calicivirus (FCV) is a common viral infection in cats that mainly affects the respiratory system, mouth, and sometimes the joints. It’s one of the leading causes of “cat flu” and can range from mild cold-like signs to severe life-threatening illness. Understanding FCV is essential for every cat parent, especially those in multi-cat households, shelters, or rescue environments where this virus spreads easily.
📌 What is Feline Calicivirus (FCV)?
FCV is a highly contagious viral disease that targets the mouth, nose, throat, and sometimes the lungs and joints. It belongs to the same family of viruses that cause colds in humans, but rest assured—FCV does not spread to humans or dogs.
It’s one of the most common causes of upper respiratory illness in cats, alongside feline herpesvirus (FHV-1).
🦠 How FCV Spreads
FCV spreads through:
- Direct contact – infected saliva, nasal discharge, or eye secretions.
- Shared items – food bowls, litter boxes, bedding, and grooming tools.
- Human contact – owners can carry the virus on hands or clothing.
Virus survival: FCV is hardy, living outside a cat for up to a month in a moist environment. This makes shelters and boarding facilities high-risk spaces without proper disinfection.
🚨 Symptoms of Feline Calicivirus
Symptoms typically appear within 2–10 days of exposure:
- Sneezing 🤧
- Nasal congestion and runny nose 👃
- Watery or goopy eyes 👀
- Mouth ulcers – painful sores on the tongue, gums, or lips
- Drooling and bad breath 🦷
- Fever 🌡️
- Lethargy 💤
- Loss of appetite 🍽️ (common because cats can’t smell food)
- Limping or joint pain (seen in some FCV strains)
- In severe cases: pneumonia, difficulty breathing, or swelling in face/legs
🔍 Diagnosis of FCV
Your vet will use:
- History & symptoms – nasal discharge plus mouth ulcers strongly indicate FCV.
- PCR swabs – from the eyes or throat to confirm the virus.
- Bloodwork & X-rays – to rule out other illnesses and complications like pneumonia.
💊 Treatment for FCV
There is no cure for the virus itself, but treatment manages symptoms until the cat’s immune system clears the infection.
1. Supportive Care:
- IV or subcutaneous fluids if dehydrated.
- Assisted feeding (syringe or feeding tube) if food refusal continues.
2. Medications:
- Antibiotics – not for the virus, but to treat secondary bacterial infections.
- Antiviral medications like famciclovir may help in severe cases.
- Pain relief for cats with painful mouth ulcers.
- Eye drops or ointments if conjunctivitis is present.
- Nasal drops or nebulizer therapy to clear congestion.
⚠️ Warning: Never use human cold, flu, or pain medications for cats. Many are toxic or fatal. Always coordinate with your veterinarian.
🥣 Diet for Cats with FCV
Nutrition is critical because cats may not eat due to congestion or mouth pain.
- Offer soft, strong-smelling foods (canned pate, tuna in water, boiled chicken).
- Serve meals warmed slightly to enhance aroma.
- Offer pureed baby food (meat-only, no onion/garlic).
- Syringe-feed or use liquid recovery diets if appetite is gone.
- Provide fresh water and consider electrolyte supplements if directed by your vet.
🏡 Home Care for Cats with FCV
- Isolation: Keep sick cats in a separate room with their own litter box, bed, and bowls.
- Hygiene: Wash hands, clothes, and disinfect shared areas daily.
- Steam therapy: Bring your cat into a steamy bathroom to ease breathing.
- Wipe eyes and nose: Use warm damp cotton balls or pads.
- Reduce stress: Provide a quiet, warm environment. Stress lowers immunity and worsens symptoms.
🛡️ Prevention of FCV
Vaccination is the most effective protection.
- FCV is part of the core FVRCP vaccine (Feline Viral Rhinotracheitis, Calicivirus, Panleukopenia).
- Vaccination doesn’t fully prevent infection, but it reduces severity and spread.
- Keep unvaccinated kittens away from exposure until fully vaccinated.
Other preventive steps:
- Practice strict hygiene in multi-cat homes.
- Quarantine new cats for at least 2 weeks and test if from shelters.
- Immediately isolate cats showing sneezing, eye discharge, or ulcers.
🌱 Quality of Life with FCV
- Many cats recover fully from FCV within 1–2 weeks.
- Some cats become chronic FCV carriers, shedding the virus for months or years. Flare-ups may occur during stress.
- Cats with chronic oral ulcers or gingivitis may need lifelong supportive care and regular vet visits.
- With good care, most FCV-positive cats live long, comfortable lives.
❓ FAQs About Feline Calicivirus
1. Is FCV deadly?
Most cats recover, but severe FCV strains can cause pneumonia or widespread inflammation. Kittens and immune-compromised cats are most at risk.
2. Can humans catch FCV?
No, FCV only affects cats. Humans can spread the virus indirectly by carrying it on their clothes or hands.
3. Can vaccinated cats still get FCV?
Yes, but usually in a milder form with faster recovery. Vaccination reduces severity, not absolute risk.
4. How long is a cat contagious with FCV?
Cats may shed the virus for weeks to months after infection. Some remain lifelong carriers.
5. What is the difference between FCV and FHV (herpesvirus)?
Both cause cat flu, but:
- FCV often causes mouth ulcers and limping.
- FHV typically causes eye ulcers and lifelong carrier states.
💡 Final Thoughts
Feline Calicivirus is common, contagious, and uncomfortable for cats—but it’s also very manageable with prompt care, supportive treatment, and prevention through vaccination. With proper treatment, most cats recover and enjoy long, happy lives, even if they remain carriers.
✅ Key takeaway: Vaccinate, act quickly when symptoms appear, and always seek veterinary care—never give human medicine.