Delta says no to medical assistance puppies or kittens and any emotional support animals on long flights
Effective December 18, 2018: Service and support animals under four months of age are not allowed on any flight due to USDA vaccination requirements. Additionally, emotional support animals are no longer allowed to be booked on flights longer than eight hours. If you purchased your ticket prior to December 18th and have requested to travel with an emotional support animal, it will be ok to travel as originally ticketed.