Delta Air Lines is cracking down on rules when it comes to bringing emotional support animals on planes.
The airline announced Friday that passengers wishing to bring their support animal on board will have to show proof of health and vaccinations 48 hours in advance, as well as other requirements.
Travelers with a psychiatric service or support animal will have to have a signed document "confirming that their animal can behave to prevent untrained, sometimes aggressive household pets from traveling without a kennel in the cabin," Delta said.
The new requirements kick in on March 1.
Delta cited animal "incidents" increasing 84% since 2016, including urination/defecation, biting and even a widely reported attack by a 70-pound dog. Employees have even reported barking, growling and biting from service and support animals.
Last year, a passenger's emotional support dog bit the face of the traveler in the next seat aboard a Delta flight.
"The rise in serious incidents involving animals in flight leads us to believe that the lack of regulation in both health and training screening for these animals is creating unsafe conditions across U.S. air travel," said John Laughter, Delta's senior vice president for corporate safety, security and compliance.
The airline carries about 700 assistance animals each day and about 250,000 passengers per year with service or emotional-support animals.
Delta hinted that the now-strict rule is a result of customers abusing the system in the past.
"Customers have attempted to fly with comfort turkeys, gliding possums known as sugar gliders, snakes, spiders and more," Delta said. "Ignoring the true intent of existing rules governing the transport of service and support animals can be a disservice to customers who have real and documented needs."
"This new policy is our first step in better protecting those who fly with Delta with a more thoughtful screening process,” Laughter said.
The Association of Flight Attendants, a union that represents some 50,000 flight attendants across several airlines, including United, cheered the decision.
"We need better regulations in place to protect the rights of people with disabilities and our veterans who legitimately need to travel with these animals," said Sara Nelson, president of the union. "We know first-hand that untrained animals can risk the safety, health and security of the passengers and crew."
The Department of Transportation, which held discussions in 2016 with mental and physical disability rights groups about which animals should be allowed in airplane cabins, said it will monitor Delta's policy to make sure it is in line with the rights of passengers with disabilities who travel with service animals.
Other airlines may soon follow suit.
"We are looking at additional requirements to help protect our team members and our customers who have a real need for a trained service or support animal," said American Airlines spokesman Ross Feinstein. "Unfortunately, untrained animals can lead to safety issues for our team, our passengers and working dogs onboard our aircraft. We agree with Delta's efforts and will continue to support the rights of customers, from veterans to people with disabilities, with legitimate needs."