Warning: This article contains discussion of cancer which some readers may find distressing.

A woman has shared her story about how her dog detected a peculiar symptom that was later diagnosed as cancer.

In June 2023, 30-year-old Breanna Bortner received the shocking diagnosis of breast cancer.

In the weeks preceding the diagnosis, the Minnesota resident exhibited few of the typical symptoms associated with the disease.

It was, in fact, her dog Mochi's unusual behavior that led her to schedule an appointment with her doctor initially.

In the spring of 2023, the two-year-old cockapoo began focusing his attention on a specific area of Bortner's body, persistently nuzzling his head against her breast.

Although such behavior isn't entirely unusual for dogs, it was only when her sister-in-law's cockapoo, Gunner, started behaving similarly that her concern grew.

She told the Daily Mail: "It was very odd."

Bortner had heard about dogs' ability to 'sniff out' illnesses in their owners and felt compelled to see a doctor, sensing 'this wasn't good'.

She had already undergone a routine breast exam months earlier, which showed no issues.

Yet, she was blindsided by a stage 2B triple-negative invasive ductal carcinoma diagnosis shortly after - one of the most aggressive forms of breast cancer, known for its resistance to many treatments.

Although the survival rate for this specific cancer is almost 100 percent in its earliest stages, it can plummet to below 31 percent if the cancer spreads to lymph nodes and surrounding organs.

Discussing the tumor, Bortner told the Mail: "It was already an inch and a half big."

Reflecting on the earlier clear scan, she added: "That's how fast and aggressive this triple-negative breast cancer is.

"It went from non-palpable, undetectable to a noticeable lump within three months."

In addition to 16 rounds of chemotherapy, Bortner also had to undergo a year of immunotherapy and a double mastectomy in the following months.

She has since started a blog - Brave Beautiful Boobies - sharing her cancer journey, where she explained: "We really underestimate how smart [dogs] are just because they don't talk and can't communicate with us.

"But their actions clearly show us what they're tuning into or are aware of."

For context, a dog's sense of smell is estimated to be between 10,000 and 100,000 times more powerful than that of humans.

Certain breeds of service dogs are known to detect when their epileptic owner is about to have a seizure.

In Mochi's case, this was likely on the higher end of the spectrum, as her breed is a mix of two dogs known for hunting and having a keen sense of smell.

It may be that Bortner's pet detected the unique odors of volatile organic compounds (VOCs) released by cancerous cells through her breath, urine, feces, and sweat, even from beneath her skin.

Before her diagnosis, her only symptoms were increased fatigue and an itch around her breasts.

She also noticed a small lump, which she claims she wouldn't have checked if Mochi hadn't drawn her attention to it.

Shortly after March 2024, Bortner was declared cancer-free - though she still needs to undergo scans every three months to ensure the cancer hasn't returned.

Speaking of the bond she and her dog now share, she said they're inseparable.

"He really became my healing buddy," the now 31-year-old shared. "He gave me a greater purpose.

"He spent so much time with me here. That's just kind of become the norm. So now when I leave the house or he's home alone, he's been getting into the trash can and showing some new behaviors."

Reflecting on her recovery, Bortner continued: "It's pretty amazing to see it come full circle and for him to be there from the time I found the lump all the way through finding out I was cancer-free.

"He was there more than anyone else. He was my main guy."

If you’ve been affected by any of these issues and want to speak to someone in confidence, contact Macmillan’s Cancer Support Line on 0808 808 00 00, 8am–8pm seven days a week.