Updated

A woman found out she had breast cancer after her dog discovered it by sniffing her chest.

Sharon Rawlinson, 43, says her Cavalier King Charles spaniel Penny had been pestering her for months until she finally went to see her doctor.

Tests found Penny had been smelling and nuzzling at the area where an aggressive tumor was growing.

Sharon, from Newark, Notts, in the U.K., immediately began chemotherapy, and will have the tumor removed in an operation on Monday.

“Penny was pawing me for weeks," Rawlinson said. “She would gently paw me as if she was trying to get something out of my left breast, but I ignored it. When she stood on me in the middle of the night and wouldn’t get off, the pain was like a thousand bee stings, and the next day I felt bruised."

When Rawlinson found a lump she assumed it was part of the injury.

But in the back of her mind, Rawlinson knew she couldn't ignore the signs since her own mother died of breast cancer.

Last year, researchers in Germany found that specially-trained dogs could detect a tumor in 71 percent of patients.

It is thought that tumors produce chemicals, including low concentrations of alkanes and aromatic compounds, which dogs can detect.

However, there is little evidence of cases of untrained domestic dogs sniffing out cancers in their owners.

“They are far more attuned to us than any other species," said Dr. Jacqueline Boyd, course leader for animal biology at Nottingham Trent University. “There is a lot of anecdotal evidence to say dogs have detected cancers and they are very responsive to things. It doesn’t surprise me this dog detected its owner’s cancer.”

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