In this photo taken Tuesday, May 21, 2013, Pets Unstressing Passengers |PUPs| volunteer Brian Valente, left, with his dog, Finn, greet the Bloom family with their 13 month old son, Jacob, at the Los Angeles International Airport terminal. The Los Angeles International Airport has 30 therapy dogs and is hoping to expand its program. The dogs are intended to take the stress out of travel: the crowds, long lines and terrorism concerns. |AP Photo | Damian Dovarganes|

In this photo taken Tuesday, May 21, 2013, Pets Unstressing Passengers (PUPs) volunteer Brian Valente, left, with his dog, Finn, greet the Bloom family with their 13-month-old son, Jacob, at the Los Angeles International Airport terminal. The Los Angeles International Airport has 30 therapy dogs and is hoping to expand its program. The dogs are intended to take the stress out of travel: the crowds, long lines and terrorism concerns. (AP Photo/Damian Dovarganes)

LOS ANGELES (AP) — There's a new breed of dog in U.S. airports. They aren't sniffing for drugs or bombs — they're looking for people who need a friend, a belly to rub or a paw to shake.

The dogs are intended to take the stress out of travel — the crowds, long lines and terrorism concerns.

"His job is to be touched," volunteer Kyra Hubis said of Henry James, her 5-year-old golden retriever that works a few hours a week at one California airport. "I am just standing there with him. They are talking to him. If I need to answer for him, I do. But I am at the end of his leash, he's not at the end of mine."

Mineta San Jose International Airport is widely credited with introducing the airport therapy dog in the days after the Sept. 11, 2001, attacks, when flights were grounded, anxious passengers were stranded and reaching friends and relatives was nearly impossible.

Then a volunteer airport chaplain got permission to bring his dog Orion to work. He made such a difference that San Jose formalized the program and now has nine dogs. Miami International Airport now has one, and Los Angeles International Airport has 30.

You never know why people are flying, said Heidi Huebner, director of volunteers at the Los Angeles airport, which launched Pets Unstressing Passengers (PUPs) in April. Travelers might be in town for a funeral, to visit a sick family member or to attend a business meeting.

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"You can literally feel the stress levels drop. People start smiling, strangers start talking to each other and everybody walks away feeling really, really good," Huebner said.

Dogs have to be healthy, skilled, stable, well-mannered and able to work on a slack 4-foot (1.2-meter) leash, said Billie Smith, executive director of Therapy Dogs, Inc., which certifies the airport's animals. They have to be comfortable with crowds, sounds, smells — and they need to pass through security like all airport workers.

In this photo taken Tuesday, May 21, 2013, Volunteers with Pets Unstressing Passengers |PUPs| walk past the spider legged Theme Building, at the Los Angeles International Airport, the airport has 30 therapy dogs and is hoping to expand its program. The dogs are intended to take the stress out of travel: the crowds, long lines and terrorism concerns. |AP Photo | Damian Dovarganes|

In this photo taken Tuesday, May 21, 2013, Volunteers with Pets Unstressing Passengers (PUPs) walk past the spider legged Theme Building, at the Los Angeles International Airport, the airport has 30 therapy dogs and is hoping to expand its program. The dogs are intended to take the stress out of travel: the crowds, long lines and terrorism concerns. (AP Photo/Damian Dovarganes)

Handlers are taught to watch for people who fear or dislike dogs or those who might have allergies. In most cases, people approach the dogs, identifiable by the vests or bandannas they wear.

Los Angeles' dogs are as varied as its passengers. There's a long-haired Dalmatian, a Lab-pointer mix, a field spaniel, a poodle, three Australian Labradoodles, a Doberman and an Irish wolfhound named Finn.

Miami's sole dog, Casey, a 4 golden retriever, has her own website, fan mail, business cards and a role on "Airport 24/7: Miami," a weekly reality show on the Travel Channel.

"Casey is so pure and genuine," said Dickie Davis, director of terminal operations and customer service. "She's not asking for anything or selling anything. She is just a love magnet."

When Claudia McCaskill's family recently flew home from vacation in Brazil, she requested Casey meet the plane to greet her 5-year-old daughter, Carina, who is autistic. She knew Carina would be low on energy and patience, and they still had a 2.5-hour drive home.

Casey and handler Liz Miller were there with a gift basket, and Carina fell in love with the dog.

"Thank you for visiting us at the airport so I would be happy," Carina said in a video the family made for Casey.

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The dogs are also there for more difficult moments.

Before departing from San Jose, a soldier kneeled down and told Henry James: "OK, buddy, you take care of the house while I am gone," Hubis said.

A woman who said her husband of 40 years told her he wanted a divorce that morning wept on Henry's shoulder.

"He just sat there," Hubis said. "He knew. He can feel."