As the old saying goes, you can’t teach an old dog new tricks. But as one organization has shown over the course of five decades, a dog can become a veteran’s new best friend. This past Fourth of July the national nonprofit Canine Companions celebrated 50 years of providing expertly trained service dogs to veterans, free of charge. The organization has placed more than 8,300 service dogs since its inception in 1975, improving the lives of children, adults, and veterans with disabilities and to