Feline calicivirus (FCV) is a contagious virus that primarily affects cats. It is one of the main causes of upper respiratory infections in felines, leading to symptoms such as sneezing, nasal congestion, and oral ulcers. The virus spreads through direct contact with infected cats or contaminated surfaces. Vaccination is available to help protect against FCV, and it is often included in routine feline vaccinations. While most cats recover from the infection, some may develop chronic issues or complications. Proper hygiene and regular veterinary check-ups are essential for maintaining feline health and preventing the spread of feline calicivirus.