When disaster strikes, man’s best friend is often there, working on the front lines and behind the scenes of rescue efforts, helping people cope with trauma and loss.

So while medical personnel tend to the survivors of the Orlando shootings, four-legged caretakers are looking after everyone else — from family members who lost loved ones to first responders and other members of a community in shock.

A team of 11 comfort dogs are in Orlando from Lutheran Church Charities, the same group that sent its dog brigade to help in the aftermath of the Boston bombings and the Sandy Hook shooting.

"They help people relax and calm down," Tim Hetzner, president of the LCC Comfort Dogs, told ABC News.

"Your blood pressure goes down when you pet a dog, you feel more comfortable, and people end up talking," Hetzner said. "They're good listeners, they're non-judgmental, they're confidential."

The specially trained golden retrievers come from seven states — Illinois, Iowa, Wisconsin, Nebraska Tennessee, South Carolina and Texas, according to the group's website.

In addition, 60 pet therapy teams from Paws for Hope are visiting patients and families at six Orlando hospitals.

Truly man's best friend

boy hugs K-9 Parish comfort dog A boy hugs one of the Lutheran Church Charities K-9 Comfort Dogs. (Photo: LCC K-9 Comfort Dogs/Facebook)

When disasters occur, dogs do much more than just aid search-and-rescue missions. They’re often there to provide a source of comfort for us in ways that only an animal can.

In an interview with American Thinker, Debra Tosch, executive director of the Search Dog Foundation (SDF), explained how her search and rescue dog Abby was able to console a firefighter at Ground Zero. "When someone was found, work would stop, and I watched as the tears rolled down the firefighters' faces. I remember one firefighter who hugged Abby and buried his face in her neck after just finding out a fellow firefighter was found," she said.

Research show that petting dogs can lower anxiety, regulate breathing and decrease blood pressure, and a Japanese study found that simply looking at a dog can increase levels of oxytocin, a chemical released by the pituitary gland that’s associated with human bonding and affection.

But while the firefighter may have found comfort in Abby’s presence, was the dog able to empathize? Research says it’s very likely.

A 2012 study at Portugal's University of Porto found that dogs yawn even when they hear only the sound of a person yawning, providing strong evidence that dogs are able to empathize with us.

And a study at the University of London Goldsmiths College found that dogs comforted people — both their owners and strangers — when the person pretended to cry.

"I think there is good reason to suspect dogs would be more sensitive to human emotion than other species," Deborah Custance, co-author of "Animal Cognition," told Discovery News. "We have domesticated dogs over a long period of time. We have selectively bred them to act as our companions. Thus, dogs that responded sensitively to our emotional cues may have been the individuals that we would be more likely to keep as pets and breed from."

Super sniffers: The power of the nose

Riley a search and rescue do Riley, a search and rescue dog is transported out of the debris of the World Trade Center post 9/11. (Photo: Journalist 1st Class Preston Keres/U.S. Navy)

Experts estimate that one search-and-rescue or SAR dog can accomplish the work of 20 to 30 human searchers. Because of these unparalleled abilities, the number of trained SAR dogs has been rising across the United States.

Dogs make efficient searchers due to their superior vision, hearing and sense of smell. A dog’s nose is about 100 times more sensitive than a human nose, and SAR dogs are trained to locate human scents amid countless other smells. They track our scents by the 30,000 to 40,000 dead skin cells we drop every minute.

"Dogs aren’t miracle workers, but their noses are so precious," said SDF founder Wilma Melville. "They can find those people who survived a horrific ordeal."

Air-scent dogs are trained to work in specific types of terrain. Some search in wilderness settings while others search urban environments, which often can involve scouring collapsed buildings.

Because they must navigate unstable terrain, urban SAR dogs are some of the most highly trained canines. The only national standards for such dogs are the Federal Emergency Management Agency's certification standards for urban disaster work. Currently, fewer than 100 dog-handler teams in the U.S. have this FEMA certification.

In addition to air-scent dogs, there are dogs taught to seek out both skin cells and the smell of human decomposition. During major disasters, such as the 1995 Oklahoma City bombing and the 2001 collapse of the World Trade Center, both air-scent dogs and cadaver dogs were used to search for people.

This caused problems for SAR dogs because they became discouraged when they found only dead bodies. At both Oklahoma City and Ground Zero, handlers hid in rubble so that dogs could occasionally find a living person. The dogs’ desire to elicit a response from a found person may be a result of their training, which involves seeking feedback and rewards, but experts say it could also speak to a deeper connection with humans.

This story was first published in May 2013 and has been updated to reflect more recent information.