Calicivirus (FCV): The ‘Limping Kitten’ Virus#

Most owners lump all “Cat Flu” into one bucket. But Feline Calicivirus (FCV) is a very different beast from Herpes.

Herpes: Snot and Eyes.
Calici: Mouth and Joints.

If your Maine Coon kitten suddenly stops eating (because his mouth hurts) or starts limping on a back leg, Calicivirus is the prime suspect. Unlike Herpes, which hides in the nerves, Calici is a master of mutation and environmental survival.

The Signature Sign: Oral Ulcers#

While Herpes makes a cat sneeze, Calicivirus eats away at the mucous membranes. Look in your cat’s mouth.

Tongue Ulcers: Raw, red, painful sores on the tip or edges of the tongue.
Palate Ulcers: Sores on the roof of the mouth.
Drooling: Because swallowing hurts, the cat will drool and refuse food. [cite_start]This is dangerous for a Maine Coon kitten, who can drop weight rapidly[cite: 502].

The “Limping Kitten” Syndrome#

This is the symptom that terrifies owners. You wake up, and your kitten cannot walk. He is holding up a leg, or shifting weight painfully.

The Cause: The virus attacks the synovium (lining) of the joints, causing acute arthritis.
The Good News: It is usually “Transient Limping.” It looks terrible, but it typically resolves on its own in 3-4 days with pain medication and rest.

Persistence: The “Shedder” Problem#

According to Feline Husbandry, Calicivirus is a “tough” virus. [cite_start]Unlike Herpes (which dies outside the cat in minutes), Calicivirus can survive on food bowls, cages, and clothing for days or weeks[cite: 502].

Continuous Shedders: Some cats recover but continue to shed the virus in their saliva for months or even for life, infecting every new kitten that enters the home. They don’t have “latency” periods like Herpes; they are constant factories of infection.

Prevention and Cleaning#

Because Calici is a non-enveloped virus, it laughs at standard cleaners. Alcohol and pine cleaners won’t kill it. You need Bleach (1:32 dilution) or Potassium Peroxymonosulfate (Virkon). Vaccines (FVRCP) are effective at reducing severity, but because the virus mutates constantly (like the human flu), they do not prevent infection 100%.

Conclusion#

If your cat has a “cold” but isn’t sneezing much—check the tongue. Calicivirus is painful and persistent. Soft food (blended with water) is essential during an outbreak to keep them eating through the pain.

References#

Pedersen, N.C. (1991). Feline Husbandry. [cite_start]“Feline Calicivirus,” pp. 163-175[cite: 29, 502].
Radford, A.D. Feline Calicivirus: immunity and vaccination.
Wardley, R.C. Feline Calicivirus carrier state.
Journal of Feline Medicine. Limping Syndrome in kittens.
American Association of Feline Practitioners. Vaccination Guidelines.