He wrote that he was in a hospital emergency room. “But I am most worried about my Aggie ring that is not in my belongings,” the poster wrote. “I am worried that it is on the road somewhere.

For Dr. Rohn Hendricks, a beloved 70-year-old equine veterinarian, one such thing was an Aggie ring—a tradition revered by graduates of Texas A&M University. Nearly five decades after graduating ...