A flight attendant for Envoy Air was bitten by an emotional support dog aboard a flight from Texas to North Carolina, requiring the victim to get stitches, officials said.

The incident happened Monday aboard American Airlines Flight 3506 – which was operated by Envoy, a subsidiary of American Airlines — from Dallas-Fort Worth International Airport to Piedmont Triad International Airport.

The flight attendant, whose identity was not released, was examined by medical personnel when the flight touched down at the airport in Greensboro, NC, an American Airlines spokesperson said.

When he returned to Dallas-Fort Worth, he needed to get five stitches, according to the spokesperson.

The Association of Flight Attendants, a union representing nearly 50,000 flight attendants at 20 airlines, called the biting incident “completely unacceptable and inexcusable.”

“For years, AFA has supported the role trained animals can provide to passengers in the cabin, but we have also called for action in regards to setting standards for emotional support animals,” the union said.

“We need the Department of Transportation to take action now, so events like the one that happened … do not continue to occur on our planes. This is fundamentally about maintaining safety, health and security for passengers and crew, while ensuring accessibility for those who need it.”

The airline rep noted that the carrier last tightened its policies on service and emotional support animals in March.

It was not immediately clear what kind of dog bit the flight attendant.