Feline Calicivirus Infection
Learn what the condition is, how it may be detected early, how it is treated or managed, and which breeds or species are linked to it.
Condition snapshot
A concise guide to the condition’s pattern, detection, management and urgency.
Limit spread while seeking adviceSeparate affected animals when practical and obtain veterinary guidance on contacts, cleaning and return to normal mixing.
This snapshot is a general guide, not a diagnosis or treatment plan. New, severe or worsening signs require veterinary assessment.
About the condition
Feline calicivirus is a common contagious virus that causes upper respiratory and oral disease in cats. Different strains vary in virulence, so clinical signs range from mild sneezing to painful oral ulceration and, rarely, severe systemic disease. The virus is especially important in shelters, catteries and other multi-cat environments where transmission can be efficient.
Typical signs include sneezing, nasal discharge, fever, conjunctivitis and ulcers on the tongue, lips or other areas of the mouth. Oral pain can cause drooling, reluctance to eat or sudden withdrawal from food. Some strains produce transient lameness, particularly in young cats. Most infections are self-limiting, but kittens or immunocompromised cats can become more seriously ill.
A rare virulent systemic form can cause high fever, facial or limb swelling, skin lesions, jaundice and multi-organ disease with high mortality. This presentation is very different from ordinary upper respiratory calicivirus and requires intensive infection-control measures.
Calicivirus is spread through oral, nasal and eye secretions and can survive in the environment longer than feline herpesvirus. Some recovered cats continue shedding virus for extended periods.
Vaccination is a core preventive measure and reduces clinical severity, although it cannot protect against every circulating strain or completely prevent infection. Good hygiene and management of crowding remain important in group settings.
Some recovered cats become persistent carriers and may intermittently shed virus despite looking healthy. This makes calicivirus control in large populations more complicated than simply waiting until every cat stops sneezing. Vaccination, hygiene and population management all remain important even after an obvious outbreak has settled. Some strains also differ geographically.
Early signs include sneezing, fever, oral discomfort, drooling and reduced appetite. Limping in a kitten with respiratory signs can also fit calicivirus infection.
Screening & Early Detection
The mouth should be examined when a cat suddenly stops eating because tongue ulcers can be easy to miss without careful inspection.
Veterinary assessment focuses on hydration, oral pain, breathing and the possibility of pneumonia or systemic disease. PCR testing may be useful in outbreaks or severe cases, but results require context because healthy carriers can shed virus. Bacterial culture is not used to diagnose the virus itself.
Vaccination history should be reviewed, particularly in kittens and cats entering high-density environments. New arrivals in shelters or catteries should be observed for respiratory disease before mixing widely with the resident population. Environmental cleaning matters because calicivirus can remain infectious on contaminated surfaces.
Facial or limb swelling, jaundice, skin ulceration, high persistent fever or rapid deterioration raises concern for virulent systemic disease and requires urgent veterinary and infection-control attention. There is no routine screening test for healthy pet cats that reliably predicts future calicivirus illness.
Diagnosis is often clinical; PCR can identify viral RNA but does not always distinguish a harmless carrier from the cause of current signs.
Treatment & Management
Most uncomplicated cases are treated supportively. Pain relief is particularly important when oral ulcers make eating difficult. Soft, highly palatable food, hydration support and gentle cleaning of nasal discharge can help the cat maintain intake while the immune system clears the acute infection.
Antibiotics do not treat calicivirus and are reserved for clinically important secondary bacterial infection. Severe dehydration, pneumonia or inability to eat can require hospitalisation with fluids, oxygen and assisted nutrition. Cats with the rare virulent systemic form need intensive supportive care and strict infection-control measures.
In multi-cat settings, bowls, litter equipment and surfaces should be cleaned with disinfectants known to be effective against calicivirus, and symptomatic animals should be separated where practical. Because some cats continue shedding after recovery, outbreak management may require veterinary guidance beyond simply isolating visibly sick cats.
Vaccination reduces disease severity and remains important even though breakthrough infection can occur. Long-term carriers usually do not require treatment solely because they shed virus. Management is based on clinical disease and household risk rather than attempting to eliminate every positive test result.
Painful mouth ulcers may require several days of analgesia and modified food texture even after fever and sneezing begin to improve.
Breeds or species affected
Abyssinian
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American Bobtail
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American Curl
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American Shorthair
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American Wirehair
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Arabian Mau
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Aegean
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Australian Mist
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Balinese
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Bengal
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Birman
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Bombay
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British Longhair
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British Shorthair
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Burmese
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Burmilla
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Chartreux
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Chausie
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Colorpoint Shorthair
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Cornish Rex
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Cymric
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Devon Rex
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Domestic Longhair
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Domestic Medium Hair
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Domestic Shorthair
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Donskoy
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Egyptian Mau
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European Shorthair
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Exotic Shorthair
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Havana Brown
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Highlander
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Himalayan
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Japanese Bobtail
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Khao Manee
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Korat
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Kurilian Bobtail
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LaPerm
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Lykoi
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Maine Coon
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Manx
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Minuet
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Minskin
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Munchkin
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Nebelung
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Norwegian Forest Cat
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Ocicat
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Oriental Longhair
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Oriental Shorthair
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Persian
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Peterbald
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Pixiebob
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RagaMuffin
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Ragdoll
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Russian Blue
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Savannah
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Scottish Fold
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Scottish Straight
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Selkirk Rex
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Siamese
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Siberian
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Singapura
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Snowshoe
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Somali
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Sphynx
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Thai
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Tonkinese
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Toybob
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Toyger
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Turkish Angora
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Turkish Van
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Bambino
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Cheetoh
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Dwelf
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Elf Cat
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Genetta
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Kinkalow
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Lambkin
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Serengeti
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Skookum
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Ukrainian Levkoy
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