Air transport is best option available, but you have to follow the rules Right ?.
Don't Believe on Airline's policies they are so stupid, you know whats the worst part is.. they dont care bout our problems.
So do exactly what i say, i have sent more then 100 dogs & pups, you can trust me!!!
You need a health certificate don't mention your dog as a pure breed. Boxer mix should be mentioned in certificate this will skip every short nose short muzzle problems according to thr policy.
You need a Fibre Cage, costly but very comfortable,re-saleable & compact.
You can contact me for more details.
Dog Behaviour Specialist