Ask Carlos
Rules for domestic and international travel vary for each country and airline traveled, and are constantly changing. It is always best to check requirements for travel with the country's consulate and with your airline to make sure preparations are started at the appropriate time.
In general the countries/destinations with the strictest rules for pet travel are the UK, Japan, Australia, and Hawaii. At least 6 months of preparation is required, including microchipping, bloodwork (rabies titer), and rabies vaccinations. Please plan well before 6 months in advance to avoid quarantine and travel delays.
Other countries generally have shorter preparation times, but some require travel documents to be signed by state officials which can delay the process considerably. As always it is best to be prepared well in advance.
Travel domestically to Puerto Rico and to Canada generally require just a vaccination or health certificate.
Please check with your airline for their requirements for travel.