Dr. Martin Goldstein is a holistic vet who pioneered what he calls “integrative medicine,” which has saved many pets that seemed past hope. His life’s work is the subject of this documentary, which is now on Amazon Prime.

At his Smith Ridge hospital in South Salem, New York, Dr. Goldstein has treated “hopeless, terminal cases from all over the world. Most of the animals that we see already had second, third or fifth opinions before they came here. And now we are their very last hope.”

He’s been called a “charlatan” a “kook,” and a “snake oil salesman,” but, as he says in the documentary, he’s never claimed to be able to cure diseases like cancer. His approach is to treat the immune system, which sometimes leads to near miraculous recoveries. “I teach my doctors that you want to get to a point where you’re trying to support that patient’s immune system so it can heal itself.”

Among the dogs he treats in the film are 12-week-old puppy Waffles, who receives Vitamin C therapy; 15-year-old Shadow, who gets magna wave therapy, and Scooby, a 12-year-old with a tumor who is treated with cryotherapy — freezing the tumor so it can be removed.

Having a compromised immune system himself, he began to develop a holistic and nutrition-based approach to his own health in his ’20s. “In medical school, we learned how to diagnose and treat disease, but we should also be treating the immune system. And it hit me, if this works for us, why wouldn’t it work for an animal?”

He’s won over several of his most outspoken critics — including one who said he fainted after seeing the recovery of a dog with cancer.

And while director Cindy Meehl is clearly a fan (she first came to Doctor Marty as a client with a dog who was at “death’s door,”) this is not an infomercial for Dr. Goldstein’s services. The movie shows at least one of his cases that is not — sadly — not successful.

We also meet several of the vets who work with Dr. Goldstein, including Dr. Jenna, who has since taken over the running of Smith Ridge while Goldstein focuses on teaching the next generation of vets.

While dog lovers will likely tear up over the pets Doctor Marty is not able to save, the film is more hopeful than sad. And will likely give pet owners some new ideas of how to best treat their pet.

Rating: 4 out of 4 paws