Beginning in early January, emotional support animals will no longer be welcome on U.S. commercial airlines. Also, only dogs will be allowed — no more service peacocks or pigs or turkeys will fly next to their owners for free.

On December 2, the U.S. Department of Transportation issued a rule change tightening up what qualifies as a service animal under the Air Carrier Access Act to exclude animals that are not dogs trained to do work or tasks that benefit a person with a disability. Thus, airline travelers who want bring their emotional support animals on a flight will need to follow airline policies for traveling with a pet.

The DOT rule change came about because too many airline passengers game the system to bring their pets with them for free by citing Air Carrier Access Act policy and flashing a doctor’s ESA letter. These letters are often obtained for a nominal fee with a few clicks on one of a myriad of online “Doc in the Box” businesses that advertise, “Take your pet on airlines for free with this letter.”

Another reason the new regulations exclude emotional support animals is that, unlike service dogs, ESAs have no standard for obedience, or even toilet training. Over the last decade there has been increasing complaints to airlines of dog barking, aggression, biting, urinating and defecating onboard aircraft. Additionally, passengers were claiming a variety pets, including a duck, as their ESA. In response to this the DOT asked for ideas and suggestions for proposed rule changes and they received over 15,000 comments that were used to shape the new rules.

Perhaps the New Rules are Too Tight

Although the new regs are welcomed by major service dog organizations, they are significantly tighter. Perhaps too tight. In the new rules, airlines are allowed to require people traveling with a service dog to fill out a form developed by the DOT attesting to the animal’s health, behavior and toilet training.

“I’ve been calling the DOT to try and find out more about the travel forms but haven’t heard anything yet,” says Marcie Davis, author of Working Like Dogs, The Service Dog Guidebook and creator of the Working Like Dogs website.

Also, the strict guidelines exclude certain service animals that are legitimately used by disabled people. The regulations prohibit airlines from refusing a service dog based on breed, but include a gray area concerning size. Specifically, “the service animal must be able to fit within its handler’s foot space on the aircraft.”

For perspective, many disabled people use German shepherds, which are large dogs that can weigh around 90 pounds. A dog this size might be able to fit in the briefcase storage area in front of its owner’s feet, but larger service dogs, like Great Danes, may not be able to fly at all. And although miniature horses are considered a service animal under the Americans with Disabilities Act, the new DOT rule does not include them.

“This is disappointing,” says Davis. “Miniature horses, as well as large dogs like Great Danes are extremely helpful mobility animals, performing tasks like helping with transfers, or providing support and balance assistance for ambulatory individuals.” Also miniature horses are exceptional for pulling a wheelchair and, unlike a dog’s seven- to 10-year working life, they live 25 to 30 years.