Feline Herpesvirus-1 (FHV-1):

• Most common cause (approximately 50% of cases)
• Also known as Feline Viral Rhinotracheitis (FVR)
• Highly contagious
• Establishes lifelong latent infection; stress can trigger recurrence

Feline Calicivirus (FCV):

• Second most common cause (approximately 40% of cases)
• Multiple strains exist
• Often causes painful oral ulcers
• Some virulent systemic strains can be fatal

Bacterial Causes (Often secondary):

Chlamydophila felis:

• Primary cause of conjunctivitis (pink eye)
• Common secondary invader in viral infections
• Responds well to specific antibiotics

Bordetella bronchiseptica:

• Less common but can cause severe pneumonia in kittens
• Has rare zoonotic potential (can infect humans)

Mycoplasma:

• A secondary invader that complicates treatment
• Difficult to culture and identify

Key Risk Factors

High-Risk Populations:

• Kittens (due to immature immune systems)
• Senior cats (with age-related decreased immunity)
• Unvaccinated cats
• Cats in shelters, rescues, or catteries
• Multi-cat households
• Cats in stressful environments

Contributing Environmental Factors:

• Overcrowding
• Poor ventilation
• Chronic stress
• Inadequate nutrition
• High parasite burden

Recognizing the Symptoms of URI

Common Clinical Signs

Nasal Symptoms:

• Sneezing (from mild to violent fits)
• Nasal discharge (ranging from clear and watery to thick, yellow, or green)
• Congestion and noisy breathing
• Decreased or lost sense of smell (anosmia)

Ocular Symptoms:

• Eye discharge (clear, yellow, or green)
• Conjunctivitis (red, swollen eyes)
• Squinting or holding eyes closed
• Prominent third eyelid
• Corneal ulcers (particularly with FHV-1)

Oral Symptoms:

• Excessive drooling
• Painful oral ulcers (common with FCV)
• Bad breath (halitosis)
• Difficulty eating or swallowing
• Pawing at the mouth

Systemic Symptoms:

• Lethargy and depression
• Fever
• Loss of appetite (anorexia)
• Dehydration
• Swollen lymph nodes

Typical Symptom Progression

Early Stage (Days 1-3):

• Mild, occasional sneezing
• Clear nasal or ocular discharge
• Slight decrease in energy
• Appetite usually remains normal

Peak Stage (Days 3-7):

• Frequent, severe sneezing
• Thick, colored discharge from nose and eyes
• Significant eye involvement (conjunctivitis)
• Noticeably decreased appetite
• Pronounced lethargy

Recovery Stage (Days 7-14+):

• Gradual improvement in all symptoms
• Discharge decreases and clears
• Appetite returns
• Energy levels normalize

When to Seek Emergency Veterinary Care

Contact your veterinarian immediately if your cat shows any of the following:

• Difficulty breathing or open-mouth breathing
• Complete refusal to eat or drink for more than 24 hours
• Severe lethargy, weakness, or collapse
• Signs of dehydration (e.g., skin tenting, dry gums)
• High fever (over 103.5°F / 39.7°C)
• Bloody nasal discharge
• Symptoms in a very young kitten

Diagnosis: How Vets Identify URI

Standard Veterinary Examination

Your veterinarian will perform a thorough physical assessment, including:

• Checking body temperature
• Evaluating hydration status
• Assessing weight and body condition
• Listening to respiratory rate and effort
• Examining the eyes and oral cavity
• Palpating lymph nodes

Diagnostic Testing

For typical, mild cases, URI is often diagnosed based on clinical signs alone, and treatment begins immediately.

Testing may be recommended in these scenarios:

• Severe, persistent, or non-responsive cases
• Outbreaks in multi-cat households or shelters
• Chronic or frequently recurring infections

Available Diagnostic Tests:

• PCR (Polymerase Chain Reaction) Testing: The gold standard for identifying specific viral and bacterial DNA/RNA.
• Viral isolation
• Bacterial culture and sensitivity
• Conjunctival or oral swabs for cytology
• Chest X-rays (if pneumonia is suspected)

Treatment Strategies for Feline URI

Supportive Home Care for Mild Cases

Most treatment focuses on supporting the cat's own immune system.

Hydration is Critical:

• Provide constant access to fresh, clean water.
• Use multiple water stations or a cat water fountain.
• Feed wet/canned food to increase fluid intake.
• Offer low-sodium chicken or beef broth (no onions or garlic).

Nutritional Support:

• Offer highly aromatic, palatable foods to tempt a poor appetite.
• Gently warm food to enhance its smell.
• Try strong-smelling options like fish, tuna juice, or chicken baby food (no onion/garlic).
• Consider high-calorie nutritional gels if eating is insufficient.

Environmental Comfort:

• Use a humidifier or bring your cat into a steamy bathroom to ease congestion.
• Provide a warm, quiet, and stress-free resting area.
• Isolate the sick cat from other household pets.
• Ensure easy access to a clean litter box.

Nursing Care:

• Gently clean crusted eyes and nose with a warm, damp cloth.
• Apply warm compresses to relieve facial discomfort.
• Use saline (saltwater) nasal drops to loosen secretions (consult your vet first).

Medical Treatment Protocols

1. Antibiotics:

• Used to treat or prevent secondary bacterial infections; they do not work against viruses.
• Common prescriptions include Doxycycline, Clavamox (amoxicillin-clavulanate), or Azithromycin.
• A typical course lasts 7-14 days; always complete the full prescription.

2. Antiviral Medications:

• For Feline Herpesvirus (FHV-1):
  • Famciclovir: An oral antiviral medication effective for severe cases.
  • L-lysine: An amino acid supplement; its efficacy is debated, but some vets recommend it to potentially suppress viral replication.
  • Topical antiviral eye ointments (e.g., idoxuridine, cidofovir).

3. Supportive Medications:

• Anti-inflammatories: NSAIDs may be used short-term to reduce fever and discomfort.
• Eye Medications: Antibiotic or antiviral ointments/drops, and lubricating gels.
• Nebulization: Breathing in a saline mist can help loosen respiratory secretions.

When Hospitalization is Necessary

Inpatient care is crucial for severe cases. Indications for hospitalization include:

• Severe dehydration requiring intravenous (IV) fluids
• Complete anorexia, necessitating assisted feeding (syringe or feeding tube)
• Suspected or confirmed pneumonia
• Significant respiratory distress
• Severe systemic illness in very young kittens

Hospital treatments may involve: IV fluids, nutritional support, oxygen therapy, injectable medications, and intensive nursing.

Potential Complications

If not managed properly, URI can lead to serious health issues:

Secondary Infections:

• Pneumonia (a life-threatening complication)
• Chronic sinusitis
• Severe, non-healing corneal ulcers

Chronic Conditions:

• Chronic Rhinitis: Persistent inflammation of the nasal passages, leading to lifelong nasal congestion and discharge.
• Recurrent symptomatic episodes, especially in herpesvirus carriers.

Prevention: Protecting Your Cat

Vaccination is Fundamental

Core vaccines for all cats include protection against:

• Feline Viral Rhinotracheitis (FHV-1)
• Feline Calicivirus (FCV)

Standard Vaccination Schedule:

• Kittens: A series at 6-8 weeks, 10-12 weeks, and 14-16 weeks of age.
• Adults: Booster shots every 1-3 years, as recommended by your veterinarian.

Vaccine Realities:

• Vaccines significantly reduce the severity of disease but may not prevent infection entirely.
• They do not prevent a cat from becoming a latent carrier (especially of herpesvirus).
• Many strains of calicivirus exist, and vaccines may not protect against all of them.

Environmental and Stress Management

In Multi-Cat Homes:

• Quarantine new cats for at least 1-2 weeks before introduction.
• Isolate sick cats immediately.
• Provide separate food/water bowls and multiple litter boxes.
• Ensure excellent ventilation and clean frequently.

Stress Reduction Techniques:

• Provide adequate vertical and horizontal space.
• Ensure sufficient resources (food stations, water bowls, scratching posts, hiding spots).
• Use synthetic feline pheromone diffusers (e.g., Feliway).
• Maintain a consistent daily routine.

Effective Sanitation

Most URI pathogens are fragile in the environment but can be spread on hands and fomites (objects).

• Disinfect surfaces with a diluted bleach solution (1 part bleach to 32 parts water).
• Wash bedding, bowls, and toys regularly.
• Practice strict hand hygiene after handling a sick cat before touching other pets.

Special Considerations for Vulnerable Cats

Kittens

• Extremely vulnerable due to immature immunity.
• Can deteriorate rapidly from dehydration and lack of eating.
• Require immediate veterinary attention at the first sign of illness.
• Often need intensive supportive care, including warmth and assisted feeding.

Senior and Immunocompromised Cats

• Includes cats with FIV/FeLV, diabetes, or those on immunosuppressive drugs.
• Have a reduced ability to fight infection and may experience slower, more complicated recoveries.
• Often require longer, more aggressive treatment plans.

Cost Analysis of URI Treatment (2026 Estimates)

Costs can vary widely based on geography, severity, and clinic pricing.

Mild Case (Outpatient Treatment):

Moderate Case (Multiple Visits & Testing):

Severe Case (Requiring Hospitalization):

Note: An outbreak in a multi-cat household can escalate costs significantly, potentially reaching several thousand dollars for testing and treating all exposed cats.

Recovery and Long-Term Management

Expected Recovery Timeline

• Mild Cases: 7-10 days with supportive care.
• Moderate Cases: 2-3 weeks.
• Severe or Complicated Cases: 3-4 weeks or longer.

Recovery speed depends on the cat's age, overall health, the specific pathogen, and the quality of care provided.

Understanding the Chronic Carrier State

Feline Herpesvirus (FHV-1) is for life.

• Approximately 80% of recovered cats become latent carriers.
• The virus hides in nerve cells and can reactivate during periods of stress, causing mild symptoms and making the cat contagious again.
• Management focuses on stress minimization: consistent routines, environmental enrichment, and potentially L-lysine (though evidence is mixed).

Frequently Asked Questions (FAQs)

Q: Can feline URI be fatal? A: Yes. While most healthy adult cats recover, URI can be fatal for kittens, seniors, and immunocompromised cats. Certain virulent strains of calicivirus can also cause severe, fatal disease in otherwise healthy adults.

Q: Is cat URI contagious to humans or dogs? A: Generally, no. The primary viruses (FHV-1, FCV) are highly species-specific to cats. The bacteria Bordetella bronchiseptica has rare zoonotic potential, mainly posing a risk to immunocompromised people.

Q: How long is my cat contagious? A: Cats actively shed virus for 1-3 weeks during the acute infection. Herpesvirus carriers can shed intermittently for life, particularly when stressed, even if they show no symptoms.

Q: Can a vaccinated cat still get URI? A: Yes. Vaccination is not 100% protective. It is designed to reduce the severity and duration of illness. Exposure to different or novel strains (especially of calicivirus) can still cause infection.

Q: When is it safe to reintroduce my cat to others after URI? A: Wait until all clinical signs have completely resolved for at least 1-2 weeks. For known herpesvirus carriers, understand there is always a low risk of asymptomatic shedding.

Q: Do cats develop immunity after having URI? A: They develop partial, strain-specific immunity. However, a cat can get URI multiple times from different pathogens or different strains of the same virus (like calicivirus).

Last Updated: 2026 | Feline URI is a common but manageable condition. Early veterinary intervention, dedicated supportive care at home, and proactive prevention are the cornerstones of protecting your cat's health.