Delta Dog travel (US to Mex, Screw worm certificate)

Anyone travel to Mexico recently with their dog on Delta? Im flying with her to Mexico City early March and have been hearing mixed messages on forms/certificates. As of 2019 you dont need a health certificate but Ive been hearing when you fly back to the US, theyve been asking for one. Also because of the screw worm outbreak, thats another certificate you need to get while in Mex before you can travel back. Any help here appreciated if youve traveled with your dog to Mex in the past few months.