Feline distemper is the common name for the feline panleukopenia virus (FPV), also called feline parvovirus. Despite the name feline distemper, this contagious disease does not affect a cat’s temperament. Rather, FPV causes serious disease in infected cats and can be fatal.
Feline leukemia virus (FeLV) is also contagious among cats. Unlike many other viruses that enter specific cells in the body and destroy them, FeLV enters certain cells in a cat’s body and changes the cells’ genetic characteristics. This permits FeLV to continue reproducing within the cat each time infected cells divide. This allows FeLV to become dormant (inactive) in some cats, making disease transmission and prognosis (outlook) difficult to predict.