Search Search Search You must have JavaScript enabled to use this form. Topic Shelter Medicine Specific Medical Conditions (-) Feline Retroviruses Active FiltersFeline Retroviruses Group 9 Clear All Feline Leukemia Virus (FeLV) Learn more about Feline Leukemia Virus (FeLV), a viral infection that affects shelter cats. Feline Immunodeficiency Virus (FIV) Learn about Feline Immunodeficiency Virus (FIV), including prevention, clinical signs, transmission, diagnosis, treatment, and management.