(CBS Local) — Miniature horses are among the service animals approved to take on flights, according to new guidelines provided Thursday by the federal government. Service animals on planes has been the subject of much debate over the past several years, especially when the animal is a little exotic. To curb some of the debate, the U.S. Department of Transportation clarified which common service animals should almost always be allowed.

“With respect to animal species, we indicated that we would focus our enforcement efforts on ensuring that the most commonly used service animals (dogs, cats, and miniature horses) are accepted for transport as service animals,” the department said in a statement.

Here's a miniature horse on a plane pic.twitter.com/1aSt94nvDW — James Kelleher (@etienneshrdlu) October 22, 2016

While not as common as dogs, miniature horses are known to make great service animals. They can live as long as 35 years, generally stand about 2 to 3 feet tall and weigh around 100 pounds when fully grown.

This doesn’t mean that all airlines are now obligated to board therapy miniature horses by law, but if they decide to ignore the new guideline, they could face a penalty.

The statement clarifies that animals outside of dogs, cats and miniature horses must be accepted or denied flight on a case-by-case basis.

Airlines will not be subject to punishment for denying access to service animals like snakes, reptiles, ferrets, rodents and spiders, according to the DOT.

The airlines have approximately 30 days to review and revise company policies in order to comply with the new regulations.