Feline Calicivirus Infection: Current Understanding and Implications for Control Strategies

Feline calicivirus (FCV) is a highly contagious pathogen widely circulating in cat populations. FCV has been shown to be able to evade the host immune response through different mechanisms. As a result, following the acute phase of infection, some cats remain persistently infected or experience reinfection cycles with variants of the same strain or with distinct field FCVs. These animals may become asymptomatic carriers, assuming a critical role in virus transmission and posing a significant risk to susceptible cats, particularly in high-density settings. Typical clinical signs of FCV infection include upper respiratory tract disease, oral ulcerations, salivation, and gingivostomatitis. In some cases, FCV infection has also been linked to a range of other clinical manifestations, including severe virulent systemic disease with high mortality rates. Indeed, FCV diversity and evolution have led to the emergence of new genetic, antigenic, and phenotypic variants, challenging disease control. This review provides a comprehensive synthesis of FCV, including its molecular biology, epidemiology, pathogenesis and clinical manifestations. Additionally, the role of vaccination and direct prophylaxis is critically evaluated. An integrated approach is essential to mitigate FCV transmission and disease burden in feline populations.