Hamerka, 55, has cerebral palsy, a disorder where the brain has trouble controlling muscle movement.
After living in group homes, Hamerka moved into his own home more than 20 years ago with the help of charitable organization Easter Seals.
“If their goal is to live independently, then we'll work with them toward that goal and try to find ways to make that happen,” said Mark German, senior director of Easter Seals UCP North Carolina.
Then two years ago, Easter Seals set up Hamerka with a service dog organization. He did intense training in Pennsylvania to be ready to handle Duke.
“It was probably the hardest thing he ever did in his life, but he did it, because he had to learn to be the dog trainer,” Hamerka’s sister Deborah Ferguson said.
Duke learned to respond to the sounds of Hamerka’s commands.
The relationship goes both ways, with Hamerka supplying biscuit rewards and refilling Duke's water bowl.
Ferguson said Duke has made a big difference in her brother’s quality of life.
“We think he's talking more. We think he communicates more. We think he socializes more. You know - smiles more. We think he's happier,” she said.
David's service dog was trained through a group called Canine Partners for Life. It is one of several organizations that breed and train service dogs with the help of volunteer puppy raisers, like WRAL's Monica Laliberte. (To find out more about becoming a puppy raiser, e-mail her at firstname.lastname@example.org.)