How are logistics and preparations for international equestrian events dealt with?

In light of the Tokyo Olympics and how equestrian events at high level deal not only with sportsmen who need to be at their best, but also their rides, needing to be in absolute peak condition in order to enable a good performance on the field, I’m curious as to how much preparation goes into ensuring the horses are fit to compete.

Here are a few questions I came up with in order to better understand how complex equestrian logistics actually are:

• What is the main mode of transportation used to move the horses to their destination?
  • Are there any special processes to be undertaken before transportation, in order to minimise stress on the horses?
  • What special measures are taken during transportation, given that competing horses are not "common" livestock?
• How much in advance to the competition do the horses usually arrive on their destination?
• What measures are taken at the destination so the horses adequate to the climate of the region and recover from the trip?