What are the clinical signs of feline calicivirus(FCV) infection?

Symptoms of infection in cats depend on the virulence of FCV. In the early stage of infection, cats will have symptoms similar to those of feline herpes virus infection, that is, sneezing, nasal congestion, fever, increased eye and nose secretions, and the secretions change from transparent to viscous, and sometimes drooling. When the condition worsens, cats will develop oral ulcers, especially around the tongue and hard palate. It is important to note that calicivirus can cause abortion in pregnant cats.

The clinical symptoms are also different if the infection is severe calicivirus (FCV-VSD). Cats with more severe calicivirus infections may experience high fever, swelling of the face and limbs, limp walking, crusted ulcers and loss of cat hair, and may bleed from the skin and digestive tract. When the virus is more virulent, pneumonia, breathing difficulties, dry or wet rales in the lungs may occur, and kittens under 3 months old may die of pneumonia. The strain is highly contagious, with a reported mortality rate of up to 67%.