New outbreaks of a novel, highly virulent strain of feline calicivirus (FCV) have been reported in the northeastern United States. Kittens and adult cats that are infected show signs of subcutaneous swelling and edema of the face, pinnae and/or distal extremities; and ulceration and necrosis of skin in affected areas in more chronic cases. Other less consistent signs include rhinitis and conjunctivitis of variable severity, anorexia and death.

This outbreak shares features of the 1998-1999 epizootic of FCV in cats in California. Mortality in the California outbreak was reported to be 33-50% in field study cats. Multiple cases arose from cat-to-cat and fomite transmission after introduction of an affected cat into shelters, clinics or catteries. The preferred disinfectant is a 1:32 dilution of sodium hypochlorite (household bleach). Currently available FCV vaccines appear minimally effective in preventing disease by this novel, virulent isolate.