The U.S. Department of Transportation announced Thursday that airlines must allow any breed of dog as a service or support animal on their flights, directly rejecting Delta Air Line s ban on pit bulls as service animals.

The agency announced in a news release that it would not allow businesses to restrict specific breeds of service animals, ensuring that dogs as a species are accepted for transport.

Though dogs, in general, are permitted as well as other common service animals, including cats and miniature horses according to DOT regulations, airlines are allowed to decide if any other species of animal poses a direct risk.

DOTs definitions of service animals are different from the one set by the Americans With Disabilities Act, which defines a service animal strictly as a dog that has been individually trained to do work or perform tasks for an individual with a disability.

Delta announced last year that it would no longer allow pit bull type dogs as service or support animals, a policy that went into effect in July 2018.

The airline said that the policy was in response to incidents in which several employees were bitten. Delta also noted that there was an 84% increase in incidents involving service animals urinating, defecating and biting during flights since 2016.

The carrier also noted an incident in June 2017 involving a passenger who was attacked by a 50-pound dog while boarding a flight in Atlanta. The dog was described as a chocolate lab pointer mix, according to a police report obtained by the Atlanta Journal-Constitution .

The American Society for the Prevention of Cruelty to Animals had denounced Deltas ban on specific breeds, arguing that it spread false stereotypes about pit bulls.

Pit bull type dogs have long been popular family pets noted for their affection and loyalty, ASPCA President Matt Bershadker said after Deltas announcement. The airline should resist unwarranted breed prejudice and rescind its breed ban.

The Department of Transportation also clarified its regulations that directly contradict a policy Delta Air Lines introduced in December, banning emotional support pets on flights that are longer than eight hours.

According to federal regulations, passengers are allowed to bring service and emotional support animal on flights longer than eight hours as long as they can provide documentation that the animal can relieve itself without creating a sanitation or health issue during the flight.

The Departments Enforcement Office would view it to be a violation for an airline to reject a medical form or letter that meets the criteria found in the rule because of an airlines preference that the passenger use the airlines form, the DOT said.

This article has been updated with the ADAs definition of a service animal.