US airline passengers in Chicago were surprised to see an unusual passenger queueing up to board a flight: a miniature horse.
Ms Abrea Hensley was flying to Omaha, Nebraska, from Chicago's O'Hare International Airport and was taking Flirty, her service animal, on board the American Airlines flight.
Ms Hensley suffers from depression, severe anxiety and several other ailments, and relies on Flirty for medical alerts and mobility assistance, media reports said.
Besides dogs, miniature horses which have been "individually trained to do work or perform tasks for people with disabilities" are the only other service animals the US Department of Justice deems protected under the Americans With Disabilities Act, The Guardian said.
That means like any other service animal, businesses that serve the public must allow Flirty to accompany her owner.
The airline told the Today Show that it was happy to have Flirty, which has a popular Instagram page and Twitter account, on board and the crew posed with the horse for an Instagram picture.
Videos and pictures taken on board and posted on social media show Flirty standing quietly in front of Ms Hensley's seat. "It was a great experience and I learned a lot," Ms Hensley tweeted on @FlirtyTheSH.
"Flirty was fantastic and handled it all like a pro. That being said, I'm going to keep travelling by car, it's just easier on Flirty. Flying will be reserved for emergencies and such."