You are not allowed to give the dog any sedatives / calming medication because of the risk of suppressing breathing etc. Our dog was 2 when we shipped him, and, as most setters are, still in the crazy 'you did what' stage (tbh he is still like that even at 10 ). We drove to London from Yorkshire, and spent hours in a park near Heathrow, to work off as much excess energy as possible. . He howled as soon as he was put in the crate. We did our best to calm him but his howls were heard long after they took him away in his crate. He was healthy and young, and his tail started wagging the moment he set eyes on my husband at the other end. But what a smell! I don't think the dogs are checked after they are loaded. They are unloaded and you collect them from a separate cargo terminal, where AFCD have a base. There are some formalities to go through but it's pretty straightforward. We live in Tseung Kwan O (Sai Kung District), in a village.
Yeah, well that is a whole other can of worms, for which I am sure there will be many posters rubbing their hands with glee and tapping furiously. I went with assuming the OP has loads of dosh and ROA in order to directly answer the dog questions.