Feline Calicivirus in Cats: Causes, Symptoms, and Treatment

Feline calicivirus (FCV) is a common viral infection affecting cats of all ages, especially in environments where multiple cats live together. While some cats develop only mild respiratory signs, others experience persistent mouth pain, difficulty eating, and chronic inflammation that can greatly impact their daily comfort and quality of life.

Because FCV does not always appear serious in the early stages, many cases are only identified once symptoms become more severe. Understanding how this virus behaves helps cat parents seek veterinary care earlier and manage the condition more effectively.

Feline Calicivirus in Cats

What Is Feline Calicivirus (FCV)?

Feline calicivirus is an RNA virus from the Caliciviridae family. It is commonly associated with upper respiratory disease but is also a major cause of chronic inflammatory conditions of the mouth, including:

• Gingivitis

• Stomatitis

• Recurrent mouth and tongue ulcers

• Feline Chronic Gingivostomatitis (FCGS)

Unlike short-term infections, FCV may persist in the body and continue triggering inflammation, particularly in adult cats.

How Calicivirus Spreads Among Cats

FCV spreads easily through:

• Direct contact with infected cats

• Saliva, nasal discharge, and eye secretions

• Shared food bowls, litter boxes, bedding, and grooming tools

Transmission risk is highest in shelters, boarding facilities, breeding environments, and multi-cat households. Some cats become carriers, meaning they continue shedding the virus even when they appear healthy.

Common Symptoms of Calicivirus in Cats

Early or General Signs

• Fever

• Reduced activity or energy

• Sneezing or nasal discharge

• Decreased appetite

Oral and Dental Symptoms

As the disease progresses, oral involvement often becomes the most noticeable problem. Cats may develop:

• Swollen or bleeding gums

• Painful ulcers on the tongue, cheeks, or gums

• Excessive drooling

• Persistent bad breath

• Difficulty chewing or swallowing

Cats in pain may approach food but stop eating, which can lead to weight loss and frustration.

Limping Associated With FCV

Some cats—especially kittens—experience temporary joint pain and limping, commonly referred to as limping calici. Veterinary evaluation is recommended to rule out other causes and ensure proper care.

Severe or Systemic FCV

In rare cases, virulent systemic feline calicivirus (VS-FCV) may occur, leading to facial or limb swelling, high fever, and internal organ involvement. This presentation requires immediate veterinary attention.

Feline Calicivirus in Kittens

Kittens are more vulnerable due to immature immune systems. Symptoms may worsen quickly, making early veterinary assessment especially important when signs such as oral pain, limping, or lethargy are present.

How Veterinarians Diagnose FCV

Diagnosis typically involves:

• Physical and oral examination

• Review of medical and environmental history

• PCR testing to detect viral genetic material

• Exclusion of other infections such as feline herpesvirus

Veterinarians also assess disease severity and chronic inflammation to guide treatment planning.

Managing Feline Calicivirus in Cats

Managing FCV—particularly in cats with oral disease—requires a targeted approach that addresses viral activity, inflammation, and pain. In veterinary practice, management may combine supportive care with antiviral-based treatment, depending on disease severity.

Antiviral Treatment Options for FCV

For cats diagnosed with FCV-associated disease, antiviral formulations may be used under veterinary supervision as part of a long-term management plan.

CaliciX™ (15 mg EIDD-1931)

CaliciX™ is an oral antiviral capsule formulated to support cats with moderate to advanced FCV-associated oral disease.

It may be included in veterinary-guided treatment plans for:

• Chronic gingivitis and stomatitis

• Oral and tongue ulcers related to FCV

• Persistent mouth inflammation causing pain or difficulty eating

CaliciX™ is designed to support ongoing management, particularly in cats experiencing recurrent or chronic FCV symptoms.

CaliciX™ Max (30 mg EIDD-1931)

CaliciX™ Max is a higher-strength antiviral formulation intended for severe, refractory, or high-viral-load FCV cases, where standard-strength therapy may be insufficient.

Veterinary-directed use may be considered in advanced presentations such as:

• Severe Feline Chronic Gingivostomatitis (FCGS)

• Deep lingual ulceration or extensive oral lesions

• Virulent systemic feline calicivirus (VS-FCV)

The higher strength allows greater antiviral exposure with fewer capsules when dosing is determined by a licensed veterinarian.

Important Veterinary Guidance

• CaliciX™ and CaliciX™ Max are not substitutes for veterinary diagnosis or professional care

• Dosage, duration, and suitability must be determined by a licensed veterinarian

• Clinical response varies between individual cats

• Supportive care—including pain management, nutrition, dental care, and treatment of secondary infections—remains essential

Preventing Calicivirus in Cats

Risk-reduction strategies include:

• Core vaccinations

• Stress reduction in multi-cat environments

• Consistent hygiene and disinfection

• Isolation of infected cats when possible

Vaccination may not fully prevent infection but often reduces disease severity.

When to Seek Veterinary Care

Consult a veterinarian if your cat shows:

• Persistent drooling or mouth pain

• Difficulty eating or swallowing

• Weight loss

• Limping or fever

• Chronic oral inflammation

Early veterinary involvement improves comfort and long-term outcomes.

Key Takeaway

Feline calicivirus is more than a mild respiratory infection—it can cause lasting oral pain and chronic inflammation. With early recognition, veterinary guidance, and appropriate management—including antiviral support when indicated—many cats can maintain a better quality of life.

If you suspect FCV, seek professional veterinary advice promptly.

Free Consultation if Your Cat Is Affected by Feline Calicivirus (FCV)

If your veterinarian suspects or diagnoses your cat with Feline Calicivirus (FCV)—especially when symptoms such as mouth ulcers, excessive drooling, difficulty eating, or chronic oral inflammation are present—you don’t have to go through this alone.

The BasmiFIP Philippines team is here to help you better understand your cat’s condition and discuss veterinary-guided FCV management options based on educational resources and clinical experience.

Website: basmifipphilippines.com

Viber: +60 1154 1804 42‬

Instagram: basmifipph

Facebook: BasmiFIP Philippines