| Abbreviation | Definition |
|---|---|
| FIM | Functional Improvement Measurement |
| FIM | Functional Independence Measuring |
| FIO2 | Fractional Inspired O2 Concentration |
| FIOC | Fluoroscopic Intra-Operative Cholangiogram |
| FIP | Feline Infectious Peritonitis |
| FIRI | Fasting Insulin Resistance Index |
| FITH | Fire In The head |
| FITT | Frequency, Intensity, Time, Type |
| FIV | Feline Immunodeficiency Virus |
| FJRM | Full Joint Range of Motion |
| FL | Femur Length |
| FL | Flank |
| FL | FLexion |
| FL | FLuid |
| FL | FLuoride |
| FL | Folding Lip |
| FLA | Flake |
| FLC | free light-chain |
| FLEX | Flexion |
| FLEXCOL | FLEXible COLlodion |