Woman says her dog sniffed out cancer: 'It is chillingly wonderful'

A Wisconsin woman is crediting her dog with saving her life after the husky detected she had cancer.

In 2013, Stephanie Herfel went to the emergency room after experiencing intense pain in her abdomen.

"It was so bad that my yoga pants even hurt," Herfel told TODAY. "They told me I had an ovarian cyst."

A few months later, she noticed that her dog, Sierra, was acting strange.

"Sierra put her nose on my belly and pushed very intently and I just thought she missed me," Herfel explained. "On the third time, I called her on it."

The dog hid, curled up in a ball for over an hour until Herfel found her with the fur all around her eyes "soaking wet and she had the biggest eyebrow cringe I’ve ever seen."

Herfel thought Sierra must have been trying to tell her something, so she made a doctor's appointment. Shortly after, the 53-year-old was diagnosed with stage III ovarian cancer.

She was convinced Sierra was the one who discovered the cancer and saved her life. To her surprise, her doctor agreed. Dogs can use their highly evolved sense of smell to detect cancer with almost 97% accuracy, a study published earlier this year found.

Over the past six years, Herfel has had ovarian cancer on and off. Each time, Sierra has helped indicate when it's there and when it's not.

"It is chillingly wonderful ... I'm like, 'OK, it's working,'" Herfel said. "She was that accurate over the course of this journey."

She credits her pup for the longevity of her life because Sierra is "the star."

"She just changed from this really sweet pet to one that is a lifesaving member of the family that is a little like a human," she said.