Unlike Spanish, English has a strong, widespread tendency to use abbreviations whenever possible. No such thing happens in Spanish. We could say, practically as a joke to imitate the English abbreviation, things like: "Vive en USA," but this is only allowed in colloquial language.

Surfing the Internet, I just confirmed my suspicion that "Dominicana" can be used as a short form for "República Dominicana."

Notice, however, that the official name is as specified [here][1]. In documents from that country I have often seen "R.D.", but this will occur in writing, not in speech.


  [1]: http://academia.org.do/como-se-debe-hacer-referencia-a-nuestro-pais-la-republica-dominicana-o-republica-dominicana/