Susan Castriota, of Upper St. Clair, is recovering from breast cancer. A mammogram in October revealed she had stage 2 invasive lobular carcinoma. Soon after her diagnosis she said she realized one of her dogs knew she was sick long before she knew she was.

"After receiving the news of my illness, I realized that Bella, one of my beloved Havanese dogs, had been paying an inordinate amount of attention to, and sniffing, my breast when I would get up in the morning," Susan said.

Susan gave little thought at that time as Bella had always been a sniffer—smelling for every little morsel of dog food left behind by Kiki and Wilson, her other two dogs. But now she thinks Bella was trying to tell her something.

"I believe that Bella detected my illness and was attempting to send a message," she said.

Through further research, Susan said she discovered that some dogs have the ability to detect cancer and some are trained to perform the task.

"The extent to which dogs can help us to learn of, and deal with illness, is a fascinating new horizon which can benefit all of humanity—another way in which these beloved creatures are miracles possessing a sixth sense," she said.

Susan also has a newfound appreciation for mammograms.

"I deeply believe in the value of a yearly mammogram, without which my cancer would not have been diagnosed in as early a stage as it was. Whatever the cost, inconvenience, and discomfort endured in the process of having a mammogram, they pale in comparison to being told that one has advanced breast cancer," she said.

Susan is an author and illustrator of chilrden's books. Bella is featured in Wilson Won't Be Bullied! from the series Willie Wilson's Wondrous Tails.

Do you believe dogs have a sixth sense? Tell us in the comments below.

Follow us on Twitter | Like us on Facebook