Woman sues American Airlines, claims emotional support dog was locked in aircraft restroom

A Miami woman is suing American Airlines, accusing a flight attendant of mistreating her and locking her emotional support dog in an airplane bathroom for an hour.

Avigail Diveroli, who claims she suffers from severe anxiety, said her "medically necessary comfort animal," Simba, was quarantined in the bathroom during the last hour of an April flight from Miami to Los Angeles, according to the lawsuit.

At one point, the attendant, identified only as Regina in the suit, grabbed the kennel, with the dog inside, and started slamming it "with the door to the bathroom," according to the lawsuit.

Diveroli said she called the airline twice ahead of time, including the night before the flight, and claims the airline ensured her the night before the flight that Simba would be able to sit in business class with her and her family, according to the suit, filed in Miami last week.

She said she boarded the plane without an issue, but claims in her lawsuit that later on, one of the flight attendants screamed at her when she noticed the dog, saying it was against Federal Aviation Administration rules and that she would be "cuffed" once the plane landed.

Diveroli, who was traveling with her husband and her 87-year-old grandfather, said the attendant "forcefully downgraded" her to another seat mid-flight and ordered her "to lock up Simba in the bathroom for the last hour of the flight," the lawsuit said.

"This is a terrible case where AA completely ignored the mental anguish of a passenger, ignored their own carrier agreement with passengers, and violated every standard of decency," the suit said, noting that the woman was pregnant at the time. "Regina [the flight attendant] yelled at Plaintiff and her husband the whole trip, even stating so much that the dog is not allowed to be wrapped with an AA blanket."

Other flight attendants allegedly apologized for their co-worker's behavior, calling her a "sour apple," according to the lawsuit. Police escorted Diveroli off the flight upon landing, but, according to the lawsuit, they ultimately concluded that there was no crime.

She is seeking damages in excess of $75,000 and a jury trial.

American Airlines initially declined ABC News' request for comment, citing its pending litigation policy, but it released a statement on Wednesday, saying the "customer’s dog was traveling as a pet rather than an emotional support animal."

"FAA regulations require pets to stay in kennels that fit under the seat, however, this kennel didn’t fit under the seat. The flight crew tried to handle the situation in accordance with FAA regulations," the statement said. "Also, this travel was booked on a 777, which doesn’t allow pets in the premium cabin. Our team at the airport in Miami offered to rebook the passenger on a later flight, but they declined, and opted to take a seat with the pet in the main cabin."

Some airlines have taken steps to prevent passengers from abusing emotional support animal policies. Those efforts got a welcomed boost from federal officials last week when the Department of Transportation said that it was OK for airlines to ask travelers for documentation related to the animal’s training or behavior.

It said staff could require the documentation so long as “it’s reasonable to believe that the documentation would assist the airline in making a determination as to whether an animal poses a direct threat to the health or safety of others,” according to a statement from the Department of Transportation.

ABC News' Mina Kaji contributed to this report.