Traveling by air with a service animal, such as a guide dog, can involve complying with complicated rules. This is especially true for travel to international countries with varying policies toward arriving animals. Some obstacles can include an outright restriction against the import of foreign domesticated animals, even service dogs, or a lengthy quarantine in which the country can run tests to be satisfied the animal has no rabies or other illnesses that might have been contracted during transit from its home country.
It is advisable for travelers heading to a foreign destination with their service animal to check with the U.S. State Department web site at http://travel.state.gov/ for a directory of foreign countries with each one's regulations regarding service animals. The Federal Aviation Administration, which regulates air travel in the U.S. has a most welcoming policy toward service animals on domestic flights, including allowing them to travel in the airplane cabin with their passenger and avoid some vaccinations required of other animals. However, it is advisable to check an information page on traveling pets from the Federal Aviation Administration found here on the FAA web site.