Feline calicivirus causes cold-like symptoms, but so long as a cat is vaccinated, he or she shouldn’t have to suffer. The vaccine against the virus is a core vaccine given in combination with those against other serious viruses.


Feline calicivirus (FCV) typically causes upper respiratory disease in cats. It is one of the two major viral causes of respiratory infection in cats (feline herpesvirus 1 or FHV-1 is the other). Cats may experience mild symptoms but some do suffer severe, life-threatening manifestations of this infection.

Vaccine Characteristics

This is a core vaccine. All kittens and cats should receive this vaccination. It is generally given as part of a combination vaccine that also protects against FHV-1 and panleukopenia.


This vaccine is administered by subcutaneous injection (injection under the skin) or by intranasal delivery (nose drops).

Recommended Schedule

While your veterinarian is always the best guide for making vaccination decisions, according to the American Association of Feline Practitioners 2006 Feline Vaccination Guidelines, the following schedule is recommended for cats and kittens:

  1. Kittens can begin the vaccine as early as 6 weeks of age, then receive boosters every three to four weeks until 16 weeks of age.
  2. For adults and all first-time vaccinates over the age of 16 weeks, two doses, three to four weeks apart are recommended.
  3. For ongoing immunity, a single dose is given one year following the last dose of the initial series, and then every three years.


Administering a vaccine is a medical procedure, and there are times when a vaccine may not be recommended. For example, your veterinarian may advise against vaccinating an animal that is currently sick, pregnant, or may not have adequate immune system functioning to respond to a vaccination. For pets with a previous history of vaccine reactions, the potential risk of a future vaccine reaction should be weighed against the potential benefits of vaccination. These and other issues are evaluated when deciding what is best for your pet.


There is no recommended alternative to vaccination in the case of feline calicivirus.

Cats that go outdoors, live with other cats, or visit grooming or boarding facilities are at greater risk for exposure to FCV compared with cats that stay indoors and have limited contact with other cats.

Keeping sick cats separated from healthy cats can reduce the likelihood of spreading FCV. Any new kitten or cat being introduced into the home should be examined by a veterinarian as soon as possible and separated from all other household pets for a quarantine period. Any problems or signs of illness should be reported to your veterinarian before introducing the new cat to your other pets. If your cat is known or suspected to be infected with FCV, contact your veterinarian promptly to discuss how you can protect your other pets.


American Association of Feline Practitioners 2006 Feline Vaccination Guidelines

This article was reviewed by a Veterinarian.