A killer virus is attacking kittens and cats, feline infectious peritonitis, and it’s difficult to diagnose. There are really no signs you can look for that might warn you of a serious problem at the onset. The virus occurs when a cat is infected with the virulent form of feline coronavirus and it mutates in the body developing quickly to an always fatal end. Cats catch this virus through personal contact or exposure to feces. Food, water, bedding, dishes and clothing may also be sources of transmission. Kittens with poorly developed immune systems and older cats are most susceptible.