| FIV | feline immunodeficiency; forced inspiratory volume |
|---|---|
| FK | feline kidney |
| FL | fatty liver; feline leukemia; femur length; fibers of Luschka; fibroblast-like; filtration leukapher... |
| FL-2 | feline lung [cells] |
| FLV | feline leukemia virus; Friend leukemia virus |