A little white dog named Waffles will pull at your heartstrings in this involving and poignant documentary about unconventional veterinarian Marty Goldstein, whose embrace of alternative therapies puts him at odds with the veterinary establishment, even as he saves lives. Director Cindy Meehl blends interviews with a fly-on-the-wall approach as she follows Goldstein and his associates as they attempt to perform miracles in upstate New York. The dogs and cats they treat are in dire straits; so ill that other veterinarians have given up. But by employing treatments rejected by the veterinary establishment, such as acupuncture and Vitamin C infusions, Goldstein gets results. Meehl concentrates on several “hopeless” canine cases, deep-diving into their treatments and tracking the progress of some, especially Waffles, at home. Not every pet can be saved, but Goldstein’s passion for making animals’ lives better infuses every frame. The Dog Doc is an often moving, emotional rollercoaster. Bring tissues.