The United States Department of Transportation clarified what animals will be allowed in the cabin of an airplane in a new rule regarding service animals. The just announced rule provides no protections for "emotional support animals," explicitly writing them out of the category of acceptable service animals, CNN reports.

The DOT's new rule defines service animals as animals that have been "individually trained to do work or perform tasks for the benefit of a person with a disability" and adds that emotional support animals do not meet their definition. Animals that have been trained to provide psychiatric support will still be allowed on planes as will more traditional service animals like seeing-eye dogs. 

The rule also allows for more stringent control of service animal travel by individual airlines. The carriers are now allowed to require DOT forms "attesting to a service animal’s health, behavior and training" and require these forms 48 hours in advance of a flight. They also allow for a limit of two service animals and give airlines the authority to require that animals fit underneath the passenger's feet. On the other end, the rule prohibits airlines from issuing breed restrictions or requiring that service animal handlers check in in person. 

The ruling comes after several headline-grabbing incidents involving non-traditional emotional support animals on flights. In one instance, an Alabama man was injured by an aggressive dog on a Delta flight. In another, a woman attempted unsuccessfully to take a peacock on board a flight. The rule provides clarity for the airlines and passengers as to the limits of the law around support animals on flights.