Zoe, a black mare, is a service animal for preschooler Zaiden Beattie at Russian Jack Elementary School. It’s the only service horse in an Alaska school — and after multiple online searches, the only service horsePrincipal Elizabeth Hornbuckle could find at any school in the nation.

Zaiden is one of 300 children in the U.S. diagnosed with A-T, or ataxia-telangiectasia, a genetic disorder that progressively robs children of their ability to coordinate movement such as walking. Zaiden’s mother, Lesley Zacharias, a professional horse trainer, is teaching Zoe to help Zaiden walk steadily until the disease inevitably shackles him to a wheelchair.

“He moves around a lot better and has more energy if he’s got a hand on someone, either holding someone’s hand or a hand on something,” Zacharias said. “My personal goal is first grade with a pony instead of a walker.”

The head of the 10-month-old horse only rises to an adult’s waist and is almost irresistible to touch, though training protocols call for her to be petted on the neck, not the face, and only when given permission. Zoe is calm but playful, eager to play or work, and lets her owners know it by nuzzling their hands.

The sturdy, 150-pound animal began making appearances in Zaiden’s preschool classroom in January. Early training began with socialization — exposure to crowds and loud noises such as the school’s fire alarm. Now she’s learning tasks.

“She’s providing balance and mobility, and she’s learning how to pick things up and eventually hand things to him,” Zacharias said.

Zacharias describes Zaiden’s balance as “good to wobbly.”

“He trips a fair amount. He falls down a fair amount,” she said. “Some days, by the time he gets off the school bus, his legs look like they’re going to give out.”

Most people with the disease are in a wheelchair by the age of 16. A-T also causes immune system problems and a high rate of cancer, and patients generally die in their 20s, according to the National Cancer Institute.

“It’s progressive. Fatal. Basically he’s going to lose his brain cells in his cerebellum, so he’ll just continually lose motor skill ability,” Zacharias said. “But intellectually, he’s going to be there the whole time.”

U.S. Department of Justice regulations that took effect in March 2011 recognized miniature horses as serviceanimals under the Americans with Disabilities Act, and Zacharias became determined to find one to extend her son’s mobility. Her partner, Joel Beattie, was skeptical, she said, but one by one, obstacles fell.

She couldn’t find a baby horse but did locate a pregnant mare in Minnesota that had been used as a therapyhorse for children with disabilities. Nine-year-old Gwendolyn was trucked to Washington then transported by ferry and van to Anchorage by Zacharias’ sister. Zoe was born in the family’s garage in May.

Their long-time landlord surprised them and said, yes, Zaiden could have a service horse inside their rented house. A friend, Deb Turner, became a surrogate mother to the little horses, talking neighbors into letting Gwendolyn and Zoe graze on their lawns. A professional seamstress who repairs backpacks for an REI store made a custom harness for Zoe with handholds that Zaiden can grasp.

Even before Zoe was born, educators at the elementary school helped solve problems such as how to keep the horse from sliding on the hard school floors. Hornbuckle, the principal, found the answer with an online search. She learned another miniature horse owner bought shoes at a Build-A-Bear Workshop store. Zoe now has eight sets.

Many people want to know if Zoe is housebroken. The horse has defecated just twice inside the school, including once “on cue” at a staff meeting after Hornbuckle said accidents were likely to happen.

Zaiden’s teacher, Cynthia Temple, said people in the school district have offered her sympathy for having to tolerate a horse in her classroom. She said it was an easy call because it makes Zaiden’s life better.

“My goal as a teacher for all the kids is independence, regardless of their needs,” Temple said. “For Zaiden, an independent thing was putting on his coat, which was big feat, and using the zipper. Now Zoe is part of how Zaiden is going to function, walking and getting up from his chair, those little things that I can already see.”

The law gives Zaiden the right to walk with his horse into restaurants and stores, but Zacharias has been cautious about public appearances.

“I want it to be appreciated, not just allowed,” she said. “I feel a heavy responsibility in being an advocate not just for my son’s condition but also for miniature horses and for service animals.”

She’s keeping a record of her family’s experience, perhaps as a guide for others in her family’s situation.

“It would be neat to look back and have some legacy to leave when Zaiden is gone,” she said. “To have something and say, yes, this happened and it was really difficult, but look at what we were able to create out of it, and none of that would have happened if it weren’t for this situation.”