June 8, 2013 -- A beloved comfort dog retiring from his duties at an Indiana high school can now count himself among the members of the school's 2013 graduating class. Prince, a golden retriever who worked as a therapy dog at Portage High School in Portage, Ind., was honored by the school with a spot in the yearbook for his for four-and-a-half years of service. Melissa Deavers-Lowie, the yearbook advisor and journalism teacher at Portage High School, told ABC News that she and her student staff didn't initially plan to commemorate Prince's retirement in the yearbook. But once they saw he had a professional picture taken by the official yearbook photographers, they couldn't resist. "The students really love Prince and they've come to see him as a part of our family at our school," she said. "But it wasn't even one of those things where we thought, 'We're going to do this.' It was one of those, 'We'll do this and people might think it's nice.'" While the students who work on the yearbook try to keep much of its content under wraps, Deavers-Lowie said no one on the 15-person staff even thought to leak this surprise because they didn't think it would be a big deal. But when the yearbook was made available to students on June 3, Prince's spot among the graduates was the best kept secret. Prince, who was bred as a therapy dog by Lutheran Church Charities, "brings a calming influence, allowing people to open up their hearts and receive help in times of need," according to his Facebook page, which has more than 3,000 likes. Deavers-Lowie said Prince will even be at the high school's graduation on Sunday, decked out in a custom-made canine cap and gown alongside his fellow classmates.