Unless you have any reservations about sending the dogs by scheduled transport, it will cost a lot more to send them by charter.
Unless you were lucky in finding a one-way route, you could be looking at $100,000+ ...depending on size of containers and any other equipment that needed to fly.
It's a long flight and you'd need at least a 737/Electra/Antonov 12 to carry them I'd suspect. And I don't know how easy it is to take those types of aircraft into the USA.