Dieter Karkut takes Remi with him everywhere. He's ex-military and needs Remi for emotional support.

“Having something to do now, going to the dog park, going outside to play,” said Karkut of the activities he enjoys doing with her.

Animals like Remi step in during times of high stress, anxiety, or even episodes of PTSD. In many ways, they're a lifeline for their handler's. But they don't require any training.

In Remi's case, she's now on her way to becoming a service animal.

But both kinds of animals fly on airplanes for free and are not required to be caged during flight.

Dog trainer Whitley Cheatley says the problem is that some service animals are just phonies.

“I think it's abused and abuse of the system,” she said. “This is the first step to trying to curb that abuse.”

She's talking about airlines like United and Delta now requiring more documentation.

United will now need confirmation that the animal is trained to behave in public and a vaccination form signed by a veterinarian. Other airlines ask for a note from a psychologist or doctor.

Service dog owners say that such requirements could make emergency trips impossible.

“They are requiring documentation 48 hours ahead of time. It creates a new hardship on handlers who actually need these animals to go with them because they need to have these presented to the airline ahead of time,” Cheatley said.

But an official with the Association of Flight Attendants says that this is good news. They say that this will “reduce fraud and protect the legitimate need of animal assistance for passengers with disabilities and veterans.”