Feline leukemiaThe disease is caused by a retrovirus and is the most common naturally occurring lymphosarcoma and accounts for nearly 30% of feline tumors. Based on the location of the tumor, the condition is described as multi-centric form, thymic form, alimentary form and atypical form. The last mentioned form is found in non-lymphoid tissues. Diagnostic tests based on detection of viral proteins in blood by FAT and ELISA is presently available. An inactivated vaccine, developed in the USA, showed reduction in the incidence of the disease. A sub-unit vaccine has also been developed recently.