U.S. air carriers are warning passengers they may soon have to leave their emotional support rabbits, hamsters, cats and turkeys at home.

New federal rules set to go into effect next week significantly narrow the definition of service animals. As a result, emotional support animals are no longer considered service animals, and airlines — which previously had to make accommodations for them — will no longer be required to do so.

The issue has been hotly debated. Officials received more than 15,000 comments on the proposed rule after it was issued last January. The rule was finalized last month and goes into effect Jan. 11.

Federal officials have said the goal is to ensure safe and accessible travel. Others say they hope the change will bring order to a situation that threatened to undermine the credibility of those traveling with legitimate service animals.

The U.S. Department of Transportation now defines a service animal as a dog that has been “individually trained to do work or perform tasks for the benefit of a qualified individual with a disability, including a physical, sensory, psychiatric, intellectual, or other mental disability.”

The new rules limit the number of service animals a person may travel with to two and require individuals to file paperwork detailing their animal's behavior, training and health status before they fly.

American Airlines, which outlined its new policy Tuesday, said it will stop accepting emotional support animals Feb. 1. Animals that previously traveled as emotional support animals may still accompany passengers as carry-on or cargo pets if they meet requirements, the airline said.

American said customers traveling with service animals must complete a special form attesting to the dog's behavior, training and health 48 hours before their flight, unless the reservation is booked within 48 hours. That authorization will be valid for one year or until the expiration of its vaccinations.

“We’re confident this approach will enable us to better serve our customers, particularly those with disabilities who travel with service animals, and better protect our team members at the airport and on the aircraft,” Jessica Tyler, American’s president of cargo and vice president of airport excellence, said in a statement accompanying the new policy.

Officials at Alaska Airlines announced similar changes last week. The airline said it will continue to accept emotional support animals for reservations made before Jan. 11 for travel through Feb. 28. After that, emotional support animals no longer will be permitted.

“This regulatory change is welcome news, as it will help us reduce disturbances onboard while continuing to accommodate our guests traveling with qualified service animals,” said Ray Prentice, Alaska Airlines’ director of customer advocacy.

Other airlines, including Delta and Southwest, said they are in the process of updating their policies but welcome the changes.

“This rule will allow airlines to put safety first for all of our customers and employees, while protecting the rights of customers who have disabilities and need to travel with trained service animals,” said Adrian Gee, a Delta Air Lines spokesman. “We are currently reviewing the new rule and will continue to work with Delta’s Advisory Board on Disability to implement it in a manner that improves the experience for all our customers.”

As the definition of what was considered a service animal expanded to include animals travelers said they needed for emotional and psychological support, there was a sharp increase in the number and variety of creatures in passenger cabins. The rise sometimes fueled conflict among passengers and between passengers and crew members.

There also were reports of animals attacking passengers and crew members, as well as animals defecating in the passenger cabin. Some questioned the legitimacy of such animals because unlike other service animals, many emotional support animals were not trained.

The Transportation Department first tried to define what should be considered a service animals in 2016 through its Advisory Committee on Accessible Air Transportation, but the group was unable to resolve which species should be allowed.

In the end, department officials said they limited the definition to dogs because the vast majority of service animals are canines.