P.F.
Hi,
I have never moved internationally with my pets, just cross country. I do know that my vet said never to sedate. It can be very alarming to the pet if they wake up in the middle of the flight and that can cause more stress. One thing you might want to look into is a company that actually "ships" pets. I used Jet-A-Pet (jetapet.com). What I found is they have representatives at all airports in case there is a plane change. They book the flight for the pet, do door to door service (ie: pick up and drop off at new location). They also let you know what papers you will need to obtain. They also told me the exact type of crate size that I would need for each pet (I was flying 2 cats and 2 large dogs). Also, what I liked is if there was say an unscheduled flight landing or change a rep would be there to take your pet out of the crate, walk it, make sure it had food/water. I really felt good about using them. I am a VERY nervous flyer myself and the thought of having to bring my kids AND pets to the airport did not go over well.
I hope this helps! All the best to you!