CHICO, Calif. - Chico dog trainer Dina Zaphiris introduces us to her cancer-sniffing dogs. She's been training the animals for over 25 years. For Zaphiris, the work is personal. 

"There were two important phone calls in my life. The first was my mother who said she had cancer," she says.

The second call came from a doctor hoping to enlist Zarphiris' services to train dogs to smell out cancer. She agreed. 

Dogs trained by Zaphiris through her non-profit, In Situ Foundation are accurate 98% of the time detecting lung and breast cancer, according to a 2006 study in the Journal of Integrative Cancer Therapies. 

"The dog is an extremely powerful tool because of its nose," Zaphiris explains. "They have 300 million scent receptors in their nose compared to 5 million in a human."

The dogs are trained not to sniff bodies, but patient samples.

"The waste products from that disease come out in your breath, urine, perspiration, just like alcohol would. What we are training the dog to do is identify the waste products from cancer patients, vs healthy patients," Zaphiris says. 

It can take a dog anywhere from 6-18 months to be fully trained.

Zepharis is now partnered with Enloe Medical Center to train a dog by the same name to detect the disease.

"All we can do now is research," she says, "we can't go out and screen the public because it's not approved by the FDA."

So the work continues, for man's best friend and the future of cancer screening.