flying with mochi domestic, paperwork

We flew Bangkok to Chiang Mai with Mochi last month. He is a 5 year old husky and he weighs over 20kg so he was not going in the cabin. Everything was under cargo. The paperwork: a health certificate from the vet dated within the time the airline needs (check this, it changed for us), a copy of his vaccines and microchip, and the owner ID. Get the health certificate done at least a week before, because the vet clinic was booked out. Ask the airline about the crate size. Mochi needed a bigger one than I expected. Also ask what happens if the flight is delayed on the ground, because it can get very hot on the tarmac. Freeze a water bottle and put it in the crate. It was okay, but not fun for either of us.