Feline panleukopenia virus (FPLV) is a species of parvovirus that can infect all wild and domestic members of the felid (cat) family worldwide. It is a highly contagious viral disease of cats, kittens are most severely affected by the virus. A similar but distinct virus causes parvovirus disease in dogs. The term panleukopenia means a decrease in the number of all of the white blood cells in the body. White blood cells play a major role in immunity and are important in defending against infections and diseases. (see: Wikipedia)