As someone who travels not infrequently with my dog, a Cavalier King Charles Spaniel who has never made a peep in flight, and pays the $125 each way for him to travel, I say bravo to Delta! Honestly, despite paying the in cabin pet fee and losing a piece of carry on luggage as a result, you have more restrictions placed on you then someone who did not pay a fee. Given the airlines' desire to maximize fees, I'm really surprised this faux-therapy phenomenon hasn't been curtailed earlier. I can't wait to see the melt downs at the check in kiosks.
Please United, please adopt these "enhanced" documentation requirements!