Watch: US man books 3 seats to fly his dog, a Great Dane. 'People were absolutely gobsmacked...'

In the clip that has gained a lot of traction online, Darwin can be seen boarding the plane and then staring into the cockpit. Bogner, 27, told that it was his 5-year-old dog’s first airplane journey.

"People were absolutely gobsmacked and shocked, but everyone was so excited to see her. I've never seen so many people smiling at an airport," Bogner told New York Post.

The 140-pound canine was "definitely a shocker for people walking through the airport to see a literal horse coming towards them".

"There were no issues, she was great and the entire crew was amazing. They did joke that she got an upgrade and I didn't, but it was a very smooth trip,” he added.

According to the New York Post, Darwin was “too huge” to fit in the airline's largest cargo box, so he was obliged to purchase a row of seats to accommodate the dog.

Bogner, who is a startup founder, said that his dog spent some time on the plane’s floor but was then allowed to sit on the chairs by the crew. The airline, however, prohibits animals from sitting on seats but the attendants obliged in Darwin’s case because of her size.

As per the report in New York Post, Bogner was diagnosed with Crohn’s disease and had trained Darwin to be a service animal.

"I got Darwin as a puppy and immediately registered her as an emotional support animal due to a lot of anxiety just from growing up basically in a hospital and a lot of the trauma from having a chronic illness," Bogner mentioned in a clip. However, some people on TikTok were uncomfortable with Darwin's status as a service dog due to the "lack of formal training".

While Darwin is not able to execute some of the “advanced tasks” that service dogs usually do, she does accompany Bogner to the restroom and calms his stomach aches by resting her head on his belly.