We've long known that dogs are man's best friend, but some canines go above and beyond. Here Maria Goodavage introduces dogs who detect cancer and Parkinson's disease, or who alert people to seizures, diabetic lows or highs, and other life-threatening physical ailments. Going behind the scenes at research centers, Goodavage reveals the revolutionary ways dogs are helping those with autism, anxiety, depression, schizophrenia, and post-traumatic stress disorder, and in this humorous, passionate tribute, explains how MDs (medical dogs) are protecting us from antibiotic-resistant bugs.