If you can, take small dogs on board with you. We brought a standard poodle with us from Miami. So, he had to be in cargo. We used an approved (by AA) crate. When we arrived in Guayaquil Dec 27th, American Airlines dropped our dog and his crate from the plane onto the Tarmac, breaking the crate in two. We found him huddling inside the upside down broken crate, shaking with fear. The airline didn't bother give us an apology or explanation. He has recovered since then. We had chosen AA because of bad stories about United. BTW, customs never bothered look at the dog's documents that were so much trouble to obtain.