Feline Calicivirus

Get A Testing Quote

Feline Calicivirus

Virus Feline calicivirus (US-EPA human norovirus surrogate)
Structure Non-enveloped
Genome Single stranded RNA, positive sense
Family Caliciviridae
Primary Host Cats
Disease(s) Caused Respiratory illness, pneumonia, fever
Symptoms Runny nose/eyes, sneezing, fever, mouth ulcers
Potential Complications Pneumonia, lameness
Transmission Mode Cat-to-cat contact: 
eye/nasal/mouth fluids   

Fomite transmission: 
food/water bowls

Sites of Community Outbreaks Animal shelters
Pet stores 
Veterinary clinics
Importance of Feline Calicivirus

Feline calicivirus (FCV) is a non-enveloped member of the family Caliciviridae. It is a widely distributed virus among cats, causing upper respiratory tract infections.

Symptoms of FCV can vary depending on the strain involved. Oral lesions are common and can be accompanied by fever, nasal discharge, and conjunctivitis. Some strains can also cause limping.

Recently, highly virulent strains have been emerging that cause a severe, systemic form of the disease. These strains are known as virulent systemic feline calicivirus (VS-FCV). VS-FCV results in widespread lesions, pneumonia, and multiple organ failure. VS-FCV is most common in situations where cats from a large population, such as those found in shelters, are moved to another, naive population. The mortality rate for VS-FCV is approximately 67%.

Importance of Disinfection: Survival of Feline Calicivirus on Surfaces and Potential for Transmission via Fomites

Feline calicivirus is highly infectious and fairly hardy. It can remain infectious for several days on different surface types, including stainless steel and plastic, at ambient temperatures (22±2°C).

FCV is transmitted from cat to cat by direct contact with infected secretions or by indirect contact with contaminated fomites. This mode of transmission is especially of concern in areas like animal shelters where secretions can easily contaminate cages, food and water bowls, and even personnel. Cats can shed the virus for up to 30 days after infection, and some carrier cats can shed the virus for life.

Vaccines for FCV do exist, but these do not actually prevent development of the carrier state in cats. VS-FCV outbreaks have also occurred in vaccinated populations. Effective disinfection protocols are therefore crucial to preventing the spread of FCV.

  • D’Souza, Doris H., et al. “Persistence of caliciviruses on environmental surfaces and their transfer to food.” International journal of food microbiology108.1 (2006): 84-91.
  • Radford, Alan D., et al. “Feline calicivirus.” Veterinary research 38.2 (2007): 319-335.