Call it a sixth sense, a special connection, or just plain mystery. But whatever gift cats and dogs have that allows them to detect health conditions in their owners sure has been saving a lot of lives.

Wendy Humphreys, a mother of two from Britain, found out first-hand how powerful that gift can be when her cat Fidge sniffed out a potentially fatal health condition that even doctors hadn't detected, the Daily Mail reports.

Bewildered at first, Humphreys was compelled to visit a physician after the 10-month-old cat began jumping on her breast and continued to do so for weeks on end.

What doctors found astounded Humphreys: She had a malignant tumor in her breast about the size of a pea that could have metastasized if it hadn't been discovered early. She is now scheduled to undergo chemotherapy and credits Fidge with saving her life, according to the paper.

Studies have shown that dogs, too, can pick up on illnesses and physical ailments by detecting acute changes in people's smell. In a 2011 study, researchers in Japan conducted trials to see how well a dog could identify people with colorectal cancer. The dog had a 98 percent accuracy rate, NPR reported.

Sometimes, however, animals' aptitude for detecting changes in humans defies scientific explanation. In 2006, a cat named Oscar confounded experts by "predicting" the deaths of a number of residents at a Rhode Island nursing home. Oscar would begin hanging around people days before they passed away, according to CBS News.

"Oscar is a normal cat with an extra-normal sense for death," Dr. Joan M. Teno, professor of community health at Brown and associate medical director of Home & Hospice Care of Rhode Island, told the Boston Globe. "As a scientist, I want to offer a biological explanation for this," she said. "But I can't."

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