Delta announced the ban last year after two employees were bitten by a pit bull

Over a year after Delta Airlines banned pit bull-type dogs from traveling as service or support animals on their flights, the U.S. Department of Transportation (DOT) instructed airlines that they must allow any breed of service dog on board.

The DOT announced the news in a release on Thursday, explaining that “dogs as a species are accepted for transport.”

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“The Department’s Enforcement Office views a limitation based exclusively on breed of the service animal to not be allowed under its service animal regulation,” the DOT wrote.

The DOT added that airlines are still “permitted to find that any specific animal, regardless of breed, poses a direct threat.”

In June 2018, Delta announced that all “pit bull-type” dogs would be banned from traveling with the airline as service or emotional support animals, after two employees were bitten by a pit bull.

“We must err on the side of safety,” Delta said in a statement provided to PEOPLE at the time. “Most recently, two Delta employees were bit by a pit bull traveling as a support animal last week. We struggled with the decision to expand the ban to service animals, knowing that some customers have legitimate needs, but we have determined that untrained, pit bull-type dogs posing as both service and support animals are a potential safety risk.”

In addition to banning pit bull-type dogs, Delta also announced that passengers would be limited to one emotional support animal (ESA) per passenger.

The DOT addressed the limitation in its release on Thursday, explaining that “the Department’s disability regulation is not clear as to how many service animals may travel with a passenger with a disability.”

“Enforcement efforts will generally focus on ensuring that airlines are not restricting passengers from traveling with one ESA and a total of three service animals if needed,” the release said. “Generally, one ESA should be sufficient for emotional support, but a passenger may reasonably need more than one task-trained service animal.”