Sep 22, 2025 D[ia]ognostics!

In 2004, the U.S. Department of Agriculture launched its Beagle Brigade. The brigade consisted of sniffer dogs trained to detect up to fifty odors associated with contraband smuggling into the country. International travelers to the U.S. have likely seen and interacted with members of the Beagle Brigade as they pass through baggage claim and customs. The Beagle Brigade detects 75,000 instances of smuggled contraband each year. Sniffer dogs have also been used to detect explosives and drugs, and, more recently, wildlife biologists are using them to find wild animals of interest. There is even a dog that helps detect orca poop floating in the ocean.

With their exceptionally keen sense of smell, dogs are now being used to detect human diseases. In 1989, two British dermatologists reported in a letter to the medical journal Lancet (p.734) that a dog had detected a melanoma on its owner’s leg. The letter generated widespread media interest, likely because it claimed the dog had saved its owner’s life by identifying the melanoma early. After removing the melanoma, the dog no longer noticed the owner’s leg. Additionally, in the 1980s in the U.S., pet dogs were alerting their owners to signs of impending epileptic seizures. These reports sparked considerable interest and led to the launch (in 2001) of a U.K. charity, Support Dogs, which provides assistance and alert dogs to people with various health issues, including epilepsy and autism.

Despite these early reports, the world is only now beginning to employ canine olfactory “superpowers” to detect disease states. In 2016, a CNN news story reported that the “awesome smelling powers of dogs” had not met commercial success. Dr. Sheryl Gabram of Emory University had published a paper reporting that a dog could reliably detect breast cancer simply by sniffing the patient’s breath. However, her team was unable to raise funds for further studies. She speculated that it was not obvious how a dog’s sniffing out cancer could be developed commercially. Nevertheless, that has not discouraged two recent start-ups and their investors. Dognosis was launched in February 2024 in India, while SpotitEarly was established in Israel in 2020. The Israeli company has raised over $20 million in investor funding and recently launched a company in the U.S.

Both companies collect diagnostic samples using masks to catch volatile organic compounds (VOCs) from the breath of human subjects and then have dogs detect which of the masks contain cancer-signaling VOC patterns. According to the Dognosis website, the company is “working with one of nature’s most sophisticated olfactory sensors, the dog’s nose, coupled with proprietary sensors and ML models to detect diseases.” It is leveraging “canines’ biological intelligence and AI for decision-making.” Additionally, Dognosis argues that over forty years of peer-reviewed studies provide “evidence that diseases change the volatile organic compounds” of a human. The company cites studies reporting that dogs can reliably identify patients with malaria, Covid-19, various types of cancer and Parkinson’s. The company is still developing its AI models, but plans to send its cancer tests directly to consumers via a physician network in 2026.

Both companies report that their tests are cheaper than standard cancer diagnostics. Dognosis claims its test is more than ten times less expensive than any cancer screening package and reports that, in early studies, its technology is 96% accurate in detecting ten types of cancer. By comparison, they report that mammograms are 80-85% correct. [Note: accuracy is a composite measure that includes both the rate of false negatives (sensitivity) and false positives (specificity).]

While d[ia]ognosis of cancer is increasingly likely to be part of future medical technology, there is still medical resistance to the idea that seizure alert dogs can predict an oncoming epileptic seizure. The initial seizure-alert dogs were ordinary pets reported to be able to detect the initial stages of an epileptic seizure, allowing the sufferer to take appropriate actions to prevent injury and harm. The unpredictability of an epileptic seizure is a significant constraint on the patient’s and any caregivers’ quality of life. It is still unclear what specific signs the dogs detect that allow them to signal an oncoming seizure. However, according to a recent study of seizure alert dogs in the Netherlands, seven of 25 participants reported reductions in seizure frequency of 50% or more following the provision of a seizure-alert dog. On average, seizure frequency was reduced by 34% among the participants in the study, while the reported Quality of Life scores increased by 14% for both patients and the primary informal caregivers!

Nevertheless, the Netherlands study reported that seizure alert dogs bring benefits and challenges. The dog provides emotional support and seizure prediction, but also adds additional responsibilities for the patient. The study noted that not all adults with severe refractory epilepsy benefit equally, as evidenced by the considerable variation in outcomes and the observation that some patients decided to discontinue the seizure dog partnership.

In summary, dogs’ exceptional olfactory abilities are increasingly used for detecting diseases, building on their historic role in contraband and wildlife detection. Recent advances combine canine scent detection with AI to identify disease biomarkers, especially cancers, through breath analysis. Once again, dogs provide not only loyalty, companionship, and love for people, but they are also increasingly helping with their medical needs.