Dogs have long been considered man’s best friend, but could they also be an aid to cancer researchers?

That’s the question explored in "Heal: The Vital Role of Dogs in the Search for Cancer Cures," penned by author and journalist Arlene Weintraub.

Inspired by her sister Beth, who died of gastric cancer at 47, Weintraub spent two years researching how clinical trials on dogs have helped the development of cancer-fighting drugs for humans.

"She only lived a year beyond her diagnosis," Weintraub told CTV’s Canada AM. "And it was about that time I’m a reporter who covers health and science and I found out that dogs are having an increasing role in cancer research. And I just became captivated with this idea."

She was particularly drawn to a 2001 medical trial on dogs that led the U.S. Food and Drug Administration to approve Palladia, a drug to treat canines with cancer. The same research was later applied to develop Sutent, a cancer drug for that helps shrink advanced mast cell tumors in humans.

Compared to other animals commonly used in cancer trials, Weintraub argues that dogs are simply better candidates. She points out, for example, that many drugs that work on lab rats simply don’t work on humans.

"Rodents really don’t develop cancer naturally. They have to be engineered to have cancer," she said. "And [that’s] believed to be the main reason that the therapies don’t translate often very well to people. But dogs, just like people, do develop cancer naturally. They share our environment, they have the same risk factors we have, and that can be very instructive."

She also believes that more tests involving dogs could lead to treatments for a variety of other cancer strains in humans.

"Dogs get a lot of the same types of cancer that people get, including lymphoma, breast cancer, some of the most common cancers. And they’re recruited into clinical trials just like a person would be in a clinical trial. And the main purpose, of course, is to help the dogs and also to learn about therapies that might end up being very useful to people."

The book is a dual tale of family and science; Weintraub weaves her sister’s battle against cancer between chapters on cancer research. To bring the story full circle, she travelled to Israel to speak with the doctor who treated her sister. But when she told him about the dog research, he wasn’t exactly impressed.

"He said we don’t treat rats, we don’t treat dogs, we treat people. And it was very sobering," she said.

However, she said, the doctor also offered a glimmer of hope.

"He also did show a hint of optimism that someday there will be breakthroughs, and that we really need to embrace all of the potential routes that we can take to reach those breakthroughs."