Spirit greets the patients in the hallways, those in wheelchairs and those who are confined to bed.
In one room an elderly woman lay unresponsive with her two children, both in their 50s, at her bedside.
"The minute Spirit brushed against her, she woke up and became aware and totally animated for 20 minutes and talked about the dogs she'd had," said Koebner. "It was a poignant conversation for the three of them together."
Guilbe, who is sometimes jaded by 20 years of conventional medicine, said she has seen the holistic healing power of Spirit's visits.
Just this week the dog jumped in bed with a woman who has chronic, incurable illness.
"She had been raised on a farm in Massachusetts and just the touch and feel of the animal brought back to her the wonderful years when she was a child and there were so many dogs running around," she said.
"It opens up another piece of my heart," said Guilbe of the interaction. "We are trained to be such stoic medical providers. I learned something about Ms. G that I would not have gotten had I just treated her symptoms. I really see her as so much more human ... It makes such a difference."