How is FIP spread?
The virus that causes FIP is in fact a variant (spontaneous mutation) of a very common infection in cats. Infection with feline coronavirus (FCoV) is extremely common (probably between π and Π of all pet cats have been infected with this virus at some point), but in the vast majority of cases the virus will cause nothing more severe than transient diarrhoea. However, occasionally a variant of the virus emerges that is much more pathogenic and in this situation, unless the infected cat can control the infection with a good immune response, FIP will develop.
