Passengers flying with Southwest Airlines will only be allowed to bring cats and dogs on board as emotional support animals beginning in September, and only one per customer.
The animals must be on a leash or in a carrier at all times, the airline said.
Southwest says passengers will need to present a letter from a doctor or licensed mental health professional on the day of departure that describes the necessity of having the animal onboard.
The airline will also limit the types of trained service animals in the cabin. Only dogs, cats, and miniature horses will be allowed.
Service animals are specially trained to help people with disabilities.