We've all probably seen service dogs on flights across America, but you may have also seen other animals that were able to fly because they were dubbed emotional support animals.

Those animals, like cats, rabbits, and pigs, along with dogs without proper training, may not be able to hop a flight with you anymore because of a new proposal from the Department of Transportation. The proposal aims to increase safety and accessibility for passengers by limiting the definition of a 'service animal' to dogs that have gone through individualized training to assist with or perform tasks for someone with a disability, according to the Washington Post and the DOT's proposal.

If the proposal passes, it wouldn't mean an outright ban of all other emotional support animals on flights. Now, instead of airlines being required to allow ESAs on flights, they would be able to make a judgment call and decide on a case-by-case basis whether or not to allow the animal to fly.

The Washington Post reports that according to Airlines for America, the number of emotional support animals has skyrocketed in recent years, from 481,000 in 2016 to 751,000 in 2017. This increase in animals aboard flights has also increased the chance of conflict, which the DOT hopes to alleviate by only allowing specially-trained dogs to fly. Currently, it's really easy to register any animal as an emotional support animal, and the process doesn't require any training.

The Washington Post reports that officials in the airline industry, including Sara Nelson, the president of the Association for Flight Attendants--CWA, are singing the proposal's praises.

"Passengers claiming pets as emotional support animals has threatened the safety and health of passengers and crews in recent years while this practice skyrocketed,” Nelson said in a statement. “Untrained pets should never roam free in the aircraft cabin. Flight attendants have been hurt and safety has been compromised by untrained animals loose in the cabin.”

Advocates for people with disabilities are also on board with the new proposal.

“This is a wonderful step in the right direction for people like myself who are dependent on and reliant on legitimate service animals," Albert Rizzi, founder of My Blind Spot, told Syracuse.com. "[Some people] want to have the benefits of having a disability without actually losing the use of their limbs or senses just so they can take their pet with them.”

According to the Washington Post, DOT officials said they chose dogs for the allowance because they represent the largest group of service animals. Before a decision is made, the DOT is accepting comments and suggestions here for 60 days.