(CNN) -- It was the dog trainer's honesty that won Lisa McMillan over.
When McMillan asked the trainer whether she was able to train a dog to assist with her autistic twin boys, the dog trainer said, "I don't know anything about autism."
The mother did. And Kelli Collins knew how to train dogs. Together, they would train and raise a puppy to be a companion to the then-3-year-olds, Eric and James. Collins would work with the puppy, Caleb, on learning the boys' scent so he could find them when they bolted. He soon would learn to comfort them, almost instinctively, when they needed a friend.
Autism, a developmental disorder, affects one of every 110 children, according to the Centers for Disease Control and Prevention. People with autism often have social, communication and behavioral challenges, but to varying degrees.
Collins is a trainer for the Georgia K9 National Training Center in Canton, Georgia. Collins, with her partner, Jeff Schettler, started as a trainer for law enforcement and search and rescue dogs. She also teaches obedience to family dogs. She's been training dogs for 15 years.
The pair trained Caleb at the center's indoor and outdoor facilities, the family's home and out in social settings. They fused their search and training techniques for finding missing people with handling a child who can bolt in an instant. They taught Jennifer Fair, who lives with the McMillans, how to give directions and encourage positive behavior with the puppy in the home and on outings.
"You can create physical disability in a training environment, you can't create autism. There's so many varying degrees of autism. Each child is a little different. Even between your own children, they are very different. We can't create that in a sterile training environment," Collins said.
The pair had to learn how autistic children thought and acted. This was their first service dog. They even made a tether for Eric, inscripted with his name and stars, because that personalized the belt and made it his. Soon the training became natural for the trainers, Schettler said.
"The first time we took Caleb out and he was tethered to [Eric], the sense of freedom that child had was amazing. He was happy," Collins said. "And he never tried to really even bolt. One time we were sitting outside at a café and he went to get up and run and Lisa's first instinct was to jump up and I'm like, 'Let the dog do his job,' and the dog stayed. Eric couldn't go. She's like, 'He would've been around the corner and down the street now.' "
The training of puppies -- environmental, obedience and service -- starts at 8 weeks old and continues on for the first 1½ years of the puppy's life, Schettler said. The puppies go with the trainers everywhere -- the grocery store, post office and restaurants. Georgia K9 places the puppies in homes when the puppies are between 10 and 16 weeks old.
"We find the bonding and everything that the dog does at this age becomes second nature to them. It's almost hard-wired in."
For families or individuals looking for a service dog for autism, Collins recommends finding a program that gives not only the training, but follow-ups and continuing guidance to help with the life transition of having a service dog. The training of service dogs for autism can cost anywhere between $15,000 and $25,000.
As an occupational therapist, Amy Johnson has been working with the brothers on their life skills and challenges. She said Eric and James at first wanted little to do with the puppy but soon grew to embrace him.
"One of the best things is seeing how Caleb helps the boys in terms of safety," Johnson said. "Whether they are tethered to Caleb or tied to him, they can take them out in the community and I think for the boys, Caleb is a sense of security and comfort and it helps keep them grounded, but at the same time it gives Mom and Dad the relief knowing that they are tied to Caleb and can't get away."
Johnson said traditional therapies are still necessary, but one of the most important things is carrying therapy over into the home. That's where the service dog helps, she said.
"I think families [dealing with autism] want to always try anything they can and try anything that might work when you don't have a cure and you don't have any answers. This way it's getting a pet for your family that's a safe pet and a pet that's there to really help with your child and grow with your child."