Emotional support animals on U.S. flights are likely to be a thing of the past, following a rules’ change in December of last year that went into effect in January.

Caitlin Harvey is a spokesperson with the U.S. Department of Transportation. “An airline may ask whether the animal is a service animal, if the animal is required to accompany the passenger because of a disability, and what work or task the animal has been trained to perform. The airline may also observe the animal’s behavior to determine if the animal is a service animal and if a trained service animal will remain under the control of its handler.”

It’s good information to have, as many Americans are rushing to return to the skies after more than a year of missed travel.

“The Department of Transportation,” Harvey said, “requires airlines to allow a service animal to accompany a passenger with a disability in air transportation. Airlines have discretion to determine whether or not to require service animal users to submit DOT service animal forms. Airlines also have discretion to determine whether or not to transport animals that are not service animals (e.g., emotional support animals, pets).

It makes since to check in advance with your carrier and since it’s the airline—not the TSA—that makes the final determination.

In the past, people have taken advantage of rules that allow emotional support animals onboard flights, as a way to have their pets travel with them. Iguanas, snakes, even a peacock.