- Rabbia... to Raillietiniasis...
- Railroad... to Reactive...
- Rebound... to Redness...
- Reduced... to Reimann...
- Reinsertion... to Resistance...
- Resorption... to Reticulosarcoma...
- Reticulosis... to Retropharyngeal...
- Retroplacental... to Rhinolalia...
- Rhinolith... to Rickettsial...
- Rickettsialpox... to Ringed...
- Ringing... to Rollet...
- Rolling... to Roth...
- Rubella... to Rytand...