As part of its continuing series "CNN Heroes," the cable network this week aired a report on Karen Shirk, whose non-profit group, 4 Paws for Ability, helps partner service dogs with people with disabilities.

Interestingly, it was Shirk's own challenge in getting a service dog that led her to start 4 Paws. While working as a social worker in mental retardation and autism in the 1980s, Shirk went into respiratory arrest, leading to a diagnosis of a rare neuromuscular disease, according to the CNN report.

In a wheelchair and on a respirator, she sought a service dog so she could be more independent, but agencies turned her down, saying she was too disabled for a dog to make a difference in her life.

So Shirk got a dog on her own, a black German shepherd puppy named Ben who, with the help of a trainer, became her service dog. "He gave me a reason to get up in the morning," Shirk says. "I went from existing to living."

Knowing there must be others like her, Shirk started 4 Paws in her Xenia, Ohio apartment to help people who've been told they're ineligible to get a service dog. The dogs help kids with everything from mobility problems to seizures to autism. She developed a program to train autism assistance dogs, and of the 319 dogs she's placed since 1998, nearly 70 percent have been partnered with autistic children.

Three short CNN videos about the program, its clients, and what Shirk calls "the magic" of dogs can be found here.

"I'm sure there's some scientific explanation, but for me it will just always be magic," Shirk says of the impact service and therapy dogs can have on people. "I think the biggest thing is an accepting friend who's always there and ready to help."

(Photo: Ben, courtesy of 4PawsforAbility.org)