Pegasus, the winged, white stallion of Ancient Greek mythology, may have been the equine world's first frequent flyer, but today's Olympic horses are the real globetrotters racking up the air miles.

The biggest and heaviest competitors in the Games are heading for Rio on charter flights from Europe and North America that can take 40 horses at a time. Most have done such journeys many times before.

Vets and grooms travel with them.

Team GB Eventing Team Vet Liz Brown said, "Going on a plane, they (the horses) don't really know they're on a plane. They're very used to traveling around so when we're actually on a plane with them they normally travel very well."

Flying from Stansted were British-stabled horses from teams including New Zealand, Australia and China and all will have undergone a 14-day period under vet supervision in sterile yarding.

Dressage and showjumping horses have separate flights.

On arrival in Brazil the horses, who sleep standing up, will travel under police escort along a "bio-contained" route to the Olympic venue at Diadoro.