Cat Calicivirus: Respiratory Disease in Cats

Feline calicivirus is a major cause of upper respiratory infection in cats, causing significant suffering in cats worldwide especially in shelters.

Key Facts

Calicivirus causes up to 50% of feline upper respiratory infections
Symptoms include oral ulcers, nasal discharge, sneezing, and lethargy
Virulent systemic strains can cause severe illness with mortality rates over 60%
The virus spreads easily between cats through direct contact and shared bowls
Vaccines reduce severity but do not prevent all strains
Shelter cats face much higher exposure risk than indoor-only cats

Welfare Considerations

Calicivirus causes painful oral ulcers that make eating extremely difficult for affected cats, leading to significant suffering and weight loss. Cats in shelters experience stress that suppresses immunity, making outbreaks more frequent and severe. Virulent systemic calicivirus is particularly alarming - affected cats develop swollen faces, limb edema, and high fever, with many dying despite intensive care. Even recovered cats may become chronic carriers, perpetuating shelter outbreaks. Early identification and isolation, along with supportive care including pain management, are critical welfare interventions.

What You Can Do

Vaccinate cats against calicivirus as part of core vaccination protocols
Support local shelters with donations to fund medical care and isolation facilities
Isolate new cats before introducing them to existing household cats
Provide soft foods and warmth to cats recovering from respiratory illness
Advocate for improved shelter ventilation and sanitation standards