SAN FRANCISCO - Pigs might not fly, but LiLou the therapy pig wants to make air travel less stressful.

The five-year-old Juliana pig and her owner, Ms Tatyana Danilova, are part of San Francisco International Airport's "Wag Brigade" - a programme that brings therapy animals to the airport to cheer passengers up and help ease travel anxieties.

Dressed in a pilot's cap and with toenails painted bright red, LiLou breezes through the metal detector at airport security and trots to the departure gates.

She raises a hoof in greeting, poses for selfies and entertains departing passengers with a tune on her toy piano.

"People are very happy to get distracted from the travel, from their routines, whether they're flying on their journey for vacation or work," said Ms Danilova.

"Everybody is usually very happy and it makes them pause for a second and smile and be like, 'Oh, it's great.'"

When she's not delighting passengers at the airport, LiLou lives with Ms Danilova in her downtown San Francisco apartment, where she enjoys a diet of organic vegetables and protein pellets, sleeps in her own bed and goes for daily walks around the neighbourhood.

Ms Danilova says LiLou loves interacting with people, but, as a prey animal, doesn't like having anyone approach her from behind.

At the airport, eight-year-old Katie Schroeder, from San Ramon, California, squealed in delight as LiLou bashed out a tune on her piano, using her hooves and snout.

"I've never seen a pig in the airport. She can do tricks like a dog," she said.

Guest services manager Jennifer Kazarian says LiLou is the world's first airport therapy pig in a "Wag Brigade" programme, which includes dogs of all breeds and sizes. Ms Kazarian says LiLou has built a sense of community in the airport.

"When we first launched the programme, our main goal was to relieve stress for our passengers. However, what we have found is we have formed a connection with our passengers and it's been totally amazing," Ms Kazarian said.

All the therapy animals take part in a training programme with the San Francisco SPCA and must have a stable temperament, good manners and a friendly personality, she said.

As for little "accidents", Ms Kazarian said there have not been any issues. All the animals, including LiLou, are house-trained.

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