14 CFR § 382.73 - How do carriers determine if an animal is a service animal that must be accepted for transport? May a carrier require that a service animal be under the control of the service animal user or handler?
(a) You may rely on one or more of the factors set forth in paragraphs (a)(1) through)(3) of this section to determine if an animal is a service animal that must be accepted for transport.
(1) You may make two inquiries to determine whether an animal qualifies as a service animal. You may ask 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. You must not ask about the nature or extent of a person's disability or ask that the service animal demonstrate its work or task.
(2) You may observe the behavior of an animal. A trained service animal will remain under the control of its handler. It does not run freely around an aircraft or an airport gate area, bark or growl repeatedly at other persons or other animals on the aircraft or in the airport gate area, bite, jump on, or cause injury to people, or urinate or defecate in the cabin or gate area. An animal that engages in such disruptive behavior demonstrates that it has not been successfully trained to behave properly in a public setting and carriers are not required to treat it as a service animal without a carrier in the cabin, even if the animal performs an assistive function for a passenger with a disability.
(3) You may look for physical indicators, such as a harness or vest on the animal, to determine if the animal is a service animal.
(b) You may require that a service animal be harnessed, leashed, or otherwise tethered at all times by the service animal user or service animal handler while in areas of the airport that you own, lease or control, or on an aircraft.