Calicivirus has been around for a long time and currently we are vaccinating for the most common strain. This virus typically only causes a mild upper respiratory disease. So what is the newest information? In 2000 a new strain of calicivirus was first reported in the United States. So what does the new strain do? The new strain is called virulent hemorrhagic feline calicivirus and causes a severe systemic disease. This disease causes a respiratory infection that often turns into pneumonia. The virus also causes inflammation of the blood vessels. This can causes fluid build up under the skin and organ failure. Sixty percent of the cats infected with this virus will succumb to the disease.
The cats most likely to be infected with the virus are cats that are housed in groups, particularly catteries, breeding facilities, and shelters. The new strain appears to be a mutation of the common calicivirus and appears without warning in these environments and spreads quickly through the cats that are in the group. This doesn’t mean that other cats are not at risk as well, but if your cats stay inside and you and your cats don’t come into contact with other cats then your risk will be much lower. Unlike the common strain adult cats seem a little more susceptible to the more virulent form.
The virus is spread just like its more common counterpart through the secretions and excretions. Cats that are in direct contact with infected cats are at the most risk. It can also be spread when the infected cat sneezes on you and you touch other cats. The virus can live in the environment for a few days to weeks in a dry environment and may stay in the environments even longer, 4 weeks, in warm humid environments. At the Toledo Animal Shelter we vaccinate for the most common strain of calicivirus and if we have any cat with upper respiratory illness we isolate them immediately and use strict quarantine procedures to prevent the virus from infecting our healthy cats.
Currently there are multiple vaccines on the market. There are several that target the traditional virus and as of early 2007 there is a new vaccine that targets the virulent systemic form of the disease. The things you should know about this vaccine are that currently there are no independent studies showing the effectiveness of the vaccine. The vaccine also has an adjuvant. An adjuvant is part of the vaccine that helps make it work better, however it has also been associated with vaccine induced sarcomas. To date there have been only a dozen reported cases in the United States including in California, New England and Missouri. At the time of this article I could not find any reported cases in Ohio.
Currently the American Animal Hospital Association, the American Veterinary Medical Association, and The Ohio State Veterinary Teaching Hospital currently don’t recommend this vaccine routinely as part of their current guidelines. If you suspect your cat is at greater risk then you should discuss the risks and possible benefits of the vaccine and if you decide to get the vaccine it will require two vaccines about three weeks apart to get immunity according to the manufactures guidelines.