05/20/2026
Love this! 👍🏼😎
For several weeks, Colleen Ferguson’s German Shepherd was obsessively sniffing her mouth. This was a new behavior that she found quite odd. The dog, Inca, was only two years old, but she seemed to know something was wrong with her owner and was doing her best to let her know. Inca constantly sniffed around Ferguson’s mouth and frowned.
The dog’s persistence caused the then 60-year-old woman to become concerned, which led her to the dentist. Everything checked out fine, but Inca was still frowning after sniffing Ferguson’s mouth. This prompted Ferguson to visit her doctor to be tested for other things that might change the smell of her breath.
According to Medical News Today, diabetes can cause the breath to smell differently. Gluten intolerance and Celiac disease can also cause bad breath, according to Imperial Dental Center. Ferguson was cleared of any gut-related issues after tests from her doctor. Yet Inca would not stop telling her something was wrong. Growing more concerned about her dog’s new behavior, Ferguson decided to do a full-body scan to rule out anything unusual.
“Her behavior towards me changed, she just started homing in on my mouth. Every time she could get a sniff of my mouth she would frown,” Ferguson told The Mirror. “She just had this focused intent on my mouth, and you couldn’t push her away until you had done an outbreath. When she got that she would give me such a look and walk away. In no way did I expect lung cancer at all. It was such a shock because I am a non-smoker, and because I taught biology, I was very anti-smoking.”
Turns out, Inca was trying to tell her she had a tumor growing in her lungs. Thanks to the dog’s keen nose and insistent behavior, Ferguson was able to catch the cancer early. Before long, the science teacher was off to surgery, where doctors removed a golf-ball-sized tumor.
“The surgeon said…’that dog saved your life. We never catch it at stage one,’” Ferguson says. Learn more about the remarkable discovery below.
