Calicivirus Infection in Cats

Abstract

Feline calicivirus (FCV) is a common pathogen in domestic cats that is highly contagious, resistant to many disinfectants and demonstrates a high genetic variability. FCV infection can lead to serious or even fatal diseases. In this review, the European Advisory Board on Cat Diseases (ABCD), a scientifically independent board of experts in feline medicine from 11 European countries, presents the current knowledge of FCV infection and fills gaps with expert opinions. FCV infections are particularly problematic in multicat environments. FCV-infected cats often show painful erosions in the mouth and mild upper respiratory disease and, particularly in kittens, even fatal pneumonia. However, infection can be associated with chronic gingivostomatitis. Rarely, highly virulent FCV variants can induce severe systemic disease with epizootic spread and high mortality. FCV can best be detected by reverse-transcriptase PCR. However, a negative result does not rule out FCV infection and healthy cats can test positive. All cats should be vaccinated against FCV (core vaccine); however, vaccination protects cats from disease but not from infection. Considering the high variability of FCV, changing to different vaccine strain(s) may be of benefit if disease occurs in fully vaccinated cats. Infection-induced immunity is not life-long and does not protect against all strains; therefore, vaccination of cats that have recovered from caliciviral disease is recommended.

Vaccination and Antibody Testing in Cats

“…For FPV vaccines, this decision can be made based on the results of a positive FPV POC antibody test. Another situation in which the requirement for vaccination can be determined by antibody measurement is in immunocompromised cats (see ABCD guidelines on Vaccination of immunocompromised cats [ 11 , 25 ]).…”

“…The level of mucosal IgA is a stronger correlate of protection than blood antibody levels, but levels of mucosal antibodies cannot be measured easily [ 10 ]. Also, because of FCV strain variation in the field, the value of antibody testing in predicting protection is limited [ 11 , 12 ]. Neutralising antibody titres detected against laboratory strains of FCV might not correlate with neutralisation (protection) against field strains due to the absence of, or insufficient, cross-neutralisation.…”

Drug screening identified that handelin inhibits feline calicivirus infection by inhibiting HSP70 expression in vitro

“…FCV is a nonenveloped, positive-sense, ssRNA virus that belongs to the family Caliciviridae [6,14], and its 7-8 kb RNA genome has three ORFs, ORF1, ORF2 and ORF3 [3,6,15]. Notably, ORF2 encodes the capsid protein VP1, which includes six regions, and regions C and E are variable; thus, new mutated strains are constantly emerging [3,6,9,16]. Although commercial vaccines have been approved for preventing FCV-induced disease, whether the existing commercial vaccines exhibit cross-protection against the newly emerging FCV strains is unknown [3,9].…”

Genetic Evolution and Biological Characteristics of Feline Caliciviruses Isolated from Dogs

“…FCV is one of the important viral pathogens of upper respiratory tract disease (URTD) in domestic cats worldwide. Ulcerative disease, gingivitis-stomatitis, and limping syndrome are also FCV-specifc diseases [12]. Te disease manifestation depends on host immunity, the multicat environment, and coinfection.…”