Like humans, horses do have to have passports. While they may not have a photo like a human passport, they contain specific data on that horse and its history. The Rio Olympics' Sport Competition Manager for Eventing Alex Titan told The Express, "[The horses' passports] are full of important data, such as a detailed physical description, with diagrams, a list of competitions competed in, and a list [of] vaccinations taken." However, they also need to be microchipped, CBS 8 reports, and must have a veterinarian-issued health certificate for international export.
Horses also have a baggage allowance, however, the FEI notes that allowance includes not only water, hay, bedding, feed buckets, and equipment like saddles and bridles, but also the weight of the horse itself. Though they're also allowed a "small overnight bag with a spare headcollar (halter) and rug, in case it gets chilly."
Once on board, they get special services. According to the FEI, horses get in-flight meals and drinks— mostly hay and water, sometimes with added apple juice. NPR also notes that some even receive Gatorade, and then the occasional carrot. To ensure that there are no health issues with the horses while in the air, there are veterinarians on board, and there are also "Flying Grooms" to look after the animals and keep them calm.
They are separated by gender, however. Stallions are kept up front, while mares are in the back — all to prevent horses getting riled up during the flight.
