It used to take Mary Skrabucha five minutes to walk across the campus of The O’Farrell Charter School in San Diego. Now it takes her twenty, because with Sejera — a golden retriever — by her side, kids and teachers are constantly stopping to say hello.

Sejera isn’t your average friendly retriever. She’s a trained “facility dog” who works with Skrabucha in Family Support Services, The O’Farrell School’s one-stop shop for everything from counseling to applying for food stamps to buying towels donated from Bed Bath & Beyond. In a school that serves students whose families struggle in a variety of ways — poverty, neighborhood gangs, foster care, incarcerated parents — Sejera has become vital to many students’ emotional and psychological well-being.

This is no small job. Researchers over the last decade have amassed a sobering body of evidence showing the inability of stressed students to learn. If a kid is living in an abusive home, for example, or a violent neighborhood, his mind is physically incapable of absorbing lessons when he steps into the classroom. That’s before counting factors like hunger, physical impairment, or diagnosed learning disabilities.

That’s where dogs like Sejera come in. If an O’Farrell student is having a hard time in class, either emotionally or behaviorally, a teacher can send him to see Sejera. The student can play or cuddle with the dog, or just talk with her. Sejera’s calm, comforting presence can often be enough to enable a student to recover equilibrium and return to class. Sejera is so popular that one of the second-grade teachers has put a picture of her on his business cards. He hands them out as rewards, and his students can trade five cards for a recess with Sejera. “Another classroom was having a competition to see who could be the most well-behaved,” Skrabucha recalled. “The students chose spending time with Sejera as the reward.”