JACKSON -- It was the slide that had her slightly stumped and a little nervous.

Learning to find a missing person or wearing a harness with a handle so a boy could balance, that was easy.

But recently Cali, a 9-month-old cane corso, or Italian mastiff, hesitated at the top of the slide at Alta Elementary School. Cali had arrived in Alta the day before, a gift to Max Goodell from the Make-A-Wish Foundation.

Max, 7, has a metabolic disease, MPS III or Sanfilippo Syndrome, which causes progressive damage as the child gets older. Max has lost most of his language skills and instead uses sound, facial expressions and body language. Children with the disability begin to have trouble with balance and eventually walking as they get older.

Several years ago, Max's dad, Gordon, was reading him Peter Pan. He started thinking about the idea of the children in the story having a dog for a nanny. Gordon, a ski patroller at Grand Targhee Resort, trained avalanche dogs. He started researching service dogs.

Goodell always had three goals for his son. He wanted him to be safe, happy and have as much independence as possible. Keeping him safe but allowing him independence often conflicted.

A dog could give Max independence. If Max was tethered to a dog, he wouldn't have to be holding onto an adult's hand at all times for balance. A trained dog would make sure Max didn't wander into the road. A dog could also be his friend.

Goodell found an organization in Ontario that trained dogs in a way that could work with Max. But Wyoming was too far away. Other trainers he found had waiting lists of several years.

Instead of waiting, Goodell trained his dog, Sally, an Australian shepherd/golden retriever cross, to work with Max.

Sally kept Max out of the pool in the summer and out of the street when playing in the yard. She kept Max by her side at Music on Main concerts. With Sally there to look after Max, the Goodells were able to do more things they had stopped doing as a family. She seemed to understand his emotions.

"Dogs are just the masters of nonverbal communication," Goodell said.

While Sally did a good job of working with Max, Goodell wanted a dog that could make its own decisions, instead of looking to him. And he wanted a dog that was truly Max's dog. Sally would always see Goodell as her owner.

Goodell contacted the Make-A-Wish Foundation, which grants wishes to children with life-threatening illnesses.

It was hard to find trainers who would work with Max's disability. The organization found Bob Taylor, who came out and met the family and toured the school before coming back with Cali.

Cali comes from a strong lineage of dogs; her grandparents were considered some of the top dogs in their breed in the world.

Cane corsos are known for being able to pick up on moods. Max might not be able to say something, but Cali will know what he is looking for, Taylor said. The dogs have a special ability to pick up on brain sensitivities, the trainer said. Their presence can help calm meltdowns, panic attacks and seizures.

"What we're looking for is miracles," Taylor said. "We're training a dog to save someone's life, not just open doors. We need her to get into Max's heart and world."

Cali worked on walking next to Max while he held her harness. She was trained to stay quiet while at school. And most important, always to focus on Max. She will go everywhere Max goes.

At Alta Elementary School recently, Cali trotted by the "Please, no dogs on school property" sign.

Inside, Max waited to show her his school. He grinned and grabbed her leash when she walked in.

Since the other dog, Sally, started at school with Max a couple of weeks ago, teacher Melissa Blackburn has seen Max's independence grow. On the playground, tethered to Sally, he no longer stood directly next to a teacher, holding a hand for balance. He was willing to try new things, like the climbing wall. Kids approached him more often.

"Sally's the equalizer for him," Blackburn said.

Kids have always been kind to Max at school, but the dog gave them all a common ground. Students share stories and pictures about their pets, Blackburn said.

Two parents reported Sally helped their kids get over a fear of dogs, Blackburn said. Sally always knows, no matter what classroom she is in, that the teacher is in charge.

"She's like having another assistant," she said.

Recently, Max and Sally showed Cali the playground. Cali was calm as Max used her harness to adjust himself at the top of the slide, but then seemed confused as Max looked at her, ready to take off. She licked his face and waited. Then with a nudge, the two zipped down the slide.