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Air travel could be going to the dogs.

The Transportation Department has proposed rules that would rein in the menagerie of service animals passengers have been carrying on flights under the guise of the animals' being service pets — the new rules would allow only specially trained dogs to fly under the "service animal" designation.

If the rule takes effect, the Transportation Department would be cracking down on passengers who use the loophole to travel with pets, effectively grounding most miniature horses, turkeys, cats and other critters that travelers have taken aboard flights as service animals.

A traveler holds a dog as she checks in at American Airlines at LaGuardia Airport in New York on Nov. 24, 2015. Seth Wenig / AP file

While insisting that it "recognizes the integral role that service animals play in the lives of many individuals with disabilities," the Transportation Department said in a statement that its proposed rule is aimed at "reducing the likelihood that passengers wishing to travel with their pets on aircraft will be able to falsely claim their pets are service animals."

An approved service animal would be defined as a "dog that is individually trained to do work or perform tasks for the benefit of a person with a disability."

Sara Nelson, president of the 50,000-member Association of Flight Attendants-CWA, hailed the proposal. She said flight attendants have been injured by pets that have been let "loose in the cabin."

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"The days of Noah's Ark in the air are hopefully coming to an end," Nelson said. "Passengers claiming pets as emotional support animals have threatened the safety and health of passengers and crew in recent years while this practice skyrocketed. Untrained pets should never roam free in the aircraft cabin."

Nelson stressed that under the proposed rules, passengers could still travel with animals, but only "under their preferred carrier's pet program."

In recent years, the Transportation Department has seen the number of passenger complaints about unruly service animals on domestic and foreign airlines skyrocket from 719 in 2013 to 3,065 in 2018.

But there was little the Transportation Department could do, because, under the current rules, airlines are required to "recognize service animals regardless of species with exceptions for certain unusual species of service animals such as snakes, other reptiles, ferrets, rodents, and spiders."

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Local lawmakers, however, have responded by proposing ordinances aimed at "fake" service animals. An ordinance proposed by the powerful Chicago Alderman Edward Burke cited a report of United Airlines' having barred a woman from taking her emotional support peacock on a flight out of Newark Liberty International Airport in New Jersey.

And airlines like United, Southwest, Delta and American are already reported to have started limiting emotional support animals in cabins largely to dogs and cats in response to complaints from passengers.

The move by the airlines comes in the wake of a nationwide crackdown on people who falsely claim their pets as service and support animals so they can take them into restaurants, theaters and other public places.

Under the proposed new rules, airlines would no longer be required to accommodate travelers who want to fly with emotional cats, pigs and rabbits.

Airlines would be allowed to limit the number of service animals traveling with a single person to two and to require that an animal "fit within its handler's foot space."

The airlines would also be able to bar "service animals that exhibit aggressive behavior and that pose a direct threat to the health and safety of others," the Transportation Department statement said.

The public has 60 days to weigh in with comments, the Transportation Department said.