
Check with the airport on the receiving end what the customs requirements are and also whether the airline you will be using accepts live stock as cargo from an individual rather than a dedicated animal courier. I sent a pup to NYC and in order for the puppy to fly direct (no stopovers etc) the airline I was forced to use insisted on dealing with a registered courier. I'd recommend only ever accepting a direct flight as it's more than long enough for pups to be in a crate and deprived of food and water. Although water funnels are part and parcel of the crate, remember there is nobody there to attend to them when loaded! Sending them with food is not permitted. All this has to be taken into consideration as of course there could be flight delays, cancellations etc.
The pups will need to have specific crate sizes for their development at the time of flying. Measurements are nose to tip of tail and toe to top of head. Pups can be sent in larger than required crates but this can really hike up the costs so it's better to have the pups in crates which are the correct fit for their size and comfort throughout the journey.
Depending on the time of year there are additional costs to the airline which can come into play re temperatures in the cargo area the pups will be travelling in (particularly relevant in summer months).
Pups must be under 12 weeks of age otherwise they require a rabies vac. Your vet health certificate should show the pups' microchip or tatoo number, confirm free from parasites, disease etc and that males have two descended testicles. You should also have noted any vacs and treatments carried out on the pups before leaving your care.
If sending to show homes you will also need the appropriate UK and AKC forms plus export pedigree but these can be sent separately to the receiving owner.
There may be some other things I've forgotten - it was over 3 years ago :) but hopefully this helps meantime
regards Teri