They say that employees have also been trained to ask questions of passengers to determine the animal's classification.
For trained service animals, customers need to provide documentation stating that the animal won't need to relieve itself or can do so in a way that doesn't create a health or sanitation issue for flights scheduled to be over eight hours.
Animals that are growling, biting or attempting to bite or jumping or lunging at people in the gate area will not be allowed in the cabin, the airline said.
In announcing the policy update, American Airlines said it supports "the rights of customers, from veterans to people with disabilities, with legitimate needs for a trained service or support animal. Unfortunately, untrained animals can lead to safety issues for our team, our customers, and working dogs onboard our aircraft", the airlines said in a statement.
Emotional support animals that are permitted have to be able to fit at your feet, under your seat or in your lap. Passengers were previously allowed to provide the documents the day of their flight.
Additionally, American Airlines now says that some animals are off limits entirely because they pose a safety or public health risk.
These are the animals now also restricted from flying as support animals aboard American Airlines flights per the airline's latest animal restrictions.
According to Vox, the science behind emotional support animals is very weak.
The new ruling expands the airline's banned creatures list to include amphibians, spiders, goats, snakes, "non-household birds", or any smelly or unclean animal.
Boda cited past "incidents" regarding support animals as the airline's reason for the new restrictions. While it now intends to to enforce the existing 48-hour advanced notice and pre-clearance policy, the airlines said, it also will have procedures in place for emergency travel booked within 48 hours of departure.