ABC News December 10, 2018

Delta bans emotional support animals on long-haul flights

WATCH: Delta bans emotional support animals on long-haul flights

Delta Airlines will soon enforce new restrictions for customers who are traveling with service and emotional support animals.

Emotional support animals will no longer be allowed on flights that are longer than eight hours, the airline announced Monday.

The new policy will also prevent passengers from traveling with service and support animals that are less than 4-months-old, regardless of flight length, the airline said.

Customers who purchased tickets before Dec. 18, and requested to travel with a support animal, will still be allowed to travel as planned, according to the airline. The restrictions will take effect on Feb. 1, regardless of when tickets are purchased.

"We will continue to review and enhance our policies and procedures as health and safety are core values at Delta," John Laughter, senior vice president or corporate safety, security and compliance, said in a statement. "These updates support Delta's commitment to safety and also protect the rights of customers with documented needs - such as veterans with disabilities - to travel with trained service and support animals."

(MORE: Airlines crack down on emotional support animals in plane cabins)

Customers will be contacted by an airline representative to adjust their reservations if the new policy effects their travel plans, according to Delta.

Delta first cracked down on its emotional support animal policy in July, stating that each customer could only travel with one animal. The airline also announced it would no longer accept pit bull breeds as service or support animals.

Delta, however, is not the only major air carrier to adjust its policies for service and support animals. Earlier this year, United, American, JetBlue and Southwest separately announced new restrictions following a string of emotional support animal incidents, including a 70-pound dog that reportedly attacked a Delta passenger. In January, a woman was denied boarding because her emotional support peacock failed to meet United’s guidelines.

All support and service animals are required to be trained to behave in public and must stay near their owners at all times, according to Delta. Any animal that displays disruptive behavior may be denied boarding.