It’s well-known that dogs have acute senses, but one pooch has an extra special ability – to sniff out when her owner is ill.
Stephanie Herfel, from Wisconsin in the US, had been suffering from abdominal pain when her newly-acquired Siberian Husky, Sierra, did something unusual.
“She put her nose on my lower belly and sniffed so intently that I thought I spilled something on my clothes,” Ms Herfel told news outlet Journal Sentinel.
“She did it a second and then a third time. After the third time, Sierra went and hid. I mean hid!”
A doctor told Ms Herfel she had an ovarian cyst and sent her home with pain medication. When she came home, her dog acted strangely again, rolling up in a tight ball inside a closet.
Unnerved, Ms Herfel decided to get a second opinion. Several weeks later, a gynaecologist confirmed she had stage three ovarian cancer.
She underwent a full hysterectomy and had chemotherapy, but that wasn’t the end of the story.
After the first diagnosis in 2014, Sierra performed the same unusual ritual, once in 2015 and again a year later.
Each time, it was confirmed that cancer had returned – first to Ms Herfel’s liver, then her pelvis.
Sierra is not the only dog who seems to have an ability to detect illness in her owner.
Other dogs have been reported to be able to detect the presence of cancer.
“It’s almost like the dog knows what’s going on and is scared,” Ashley Wagner, from the Wisconsin Ovarian Cancer Alliance, told the Journal Sentinel.
“The dog didn’t want to be near her.”
Sierra reacted similarly when a friend with cancer visited Ms Herfel, who is now cancer-free and working to raise funds for women with ovarian cancer.
Ms Herfel is also planning to write a book about the special relationship she has with her dog.