"Sinatra lets me know when my sugar is spiking or dropping," Tyler told The Dodo. "He has saved my life thousands of times."
The dog has kept Tyler alive in other ways as well. Before Sinatra came along, Tyler struggled with depression arising from his health problems, and from feeling like an outcast among his peers in school. At his lowest point, he even considered suicide.
"As the years passed it started to wear on me. I started getting less and less positive," Tyler said. "But then Sinatra came and saved me from all that. He's the only friend I really need."