You need a certificate of health from a veterinarian written in Spanish, like this one:  Your animal must be microchipped (for So.Am) and rabies vaccinated. Depending upon the airline, the health certificate must be done no sooner than 5 - 10 days before the flight. If you are coming from America, the health certificate must be sent to the USDA for a stamp. You must have it sent by FEDEX (or similar) or you won't get it back in time.
Remember to reserve space for your pet with the airline and use an approved pet carrier. Go to the airline's website for details.