Bringing dog from Bangkok to Chicago?

He is a small Pomeranian and has all vaccinations complete. I think he will be aloud on the aircraft with me as he is so tiny. Was just wondering the procedures getting back into the U.S. I know they don't quarantine healthy pets for 6 months anymore, but was just wondering basic procedures. I am flying United and my layover is in Tokyo. Please do not answer just leave him here, as he is close part of me and in Bangkok I am pretty sure they treat their convicts better than dogs..thanks for the answers!...p.s. My flight is in Novermber