(NEW YORK) -- For the last week, Archibald Downer—a 65-year-old on dialysis—has been painfully poked and prodded with needles as doctors try to figure out why his fever and blood pressure won't go down.
He is bedridden among others who are sick and dying in the palliative care unit at Montefiore Hospital in the Bronx, where the days and sometimes the pain seem endless.
But once a week, a warm and loving spirit sweeps through the stressful New York City hospital, and is greeted like a breath of fresh air—Spirit, the therapy dog, that is.
With his sparkling blue eyes and friendly demeanor, the 6-year-old mutt is certified to work with patients, lifting spirits, lowering anxiety levels and easing pain—both psychological and physical.
"He jumps on my bed and lays on my legs, getting comfortable," said Downer, a retired plumber. "It's a nice way to help those who are crying from pain. The dog makes a whole lot of difference. My arm was stinging [for repeated blood draws] but it don't bother me no more."
Animals have provided emotional comfort to humans for thousands of years. According to the American Humane Society, animal-assisted therapy can help children who have suffered abuse or neglect and patients undergoing cancer treatments. Pets have also forged strong bonds with veterans' families who are coping with the effects of wartime military service.
A 2011 study published in the Journal of the American Academy of Physician Assistants reveals that patients report "feeling better" when they interact with an animal.
"It brings us closer not only to the patient, but to their family, as well," said Dr. Rose Guilbe, medical director of the palliative care unit and a family physician. "It creates a nicer working environment and takes away from the stiffness of medicine."
Spirit must follow strict hospital guidelines. His paws are disinfected before he enters the unit, he is on a leash and he wears a photo ID. And he only visits those patients who have given their consent. All people don't love dogs, and the staff understands that.
"It brings out a part of the patient we don't usually see—some joy in their personality that we don't get with opioids and other medical treatments," she said. "It also increases the communication among us in the medical community."
Copyright 2012 ABC News Radio