This is the info we have on file to answer your question. Note there may have been some changes in the fees you will be charged, but maybe not.
First, request a certification from your vet that your dog has been vaccinated for the current period for rabies and distemper.
At the airport in the DR you must ask for the animal control person (Sanidad Animal) in the customs area. They will
examine the paper the vet gave you and fill out an official entry form or permission, for which you must pay RD$100
(about US$6). Note you will have to make a special reservation for the animal to board with you and the travel cage will
count as carry-on luggage and should fit under the seat. The airline will most likely charge you a fee for carrying the
dog.