Can dogs sniff cancer? AI joins the hunt in India

When rescue dog Chloe is not tumbling across the grass on a farm outside India's tech hub Bengaluru, she is learning to sniff human breath for cancer with help from AI.

Fitted with a 3D-printed helmet and sensor-packed harness, she is part of startup Dognosis's effort to build a non-invasive cancer test.

Is it true that dogs can sniff cancer?

Yes. A growing body of global research shows dogs can be trained to detect cancer and other illnesses, including Parkinson's disease and Covid-19, through scent alone. Bengaluru startup Dognosis is now combining this ability with AI, analysing dogs' brain activity, respiration and body language to turn their reactions to scent into measurable data.

"In an hour, they can do thousands of sniffs," co-founder Akash Kulgod, 26, told AFP. "Each sniff can evaluate a sample." Dognosis hopes to launch commercially next year, which it says would make it the third company of its kind, after firms from Germany and Israel.

How could dog cancer screening help patients in India?

Early detection can make a crucial difference to cancer survival rates, but many patients in India are diagnosed only after the disease has advanced. Dog sniffs could provide an affordable first layer of screening deployed at scale, flagging potential cases for further testing. Dognosis, backed by venture capital firms including Accel India, is collaborating with government medical institutions on its research as it seeks commercial approval.

Chloe, a Labrador mix, is one of 15 dogs being coached by the startup, each wearing a customized data-gathering helmet. "It's like a doggy 'Iron Man' suit," said Kulgod, who comes from a family of doctors and studied cognitive science at the University of California, Berkeley.

How accurate is AI-assisted cancer detection by dogs?

Research suggests diseases alter the chemicals the body releases, creating distinctive odors that dogs can learn to identify. Dogs have around 300 million scent receptors, compared with about five million in humans. The testing method is simple: a patient breathes into a cotton mask for about 10 minutes, and the mask is sealed in a bag and sent to the lab, so patients never meet the dogs.

A recent Dognosis study of more than 1,500 participants across six hospitals in Karnataka state was published in the Journal of Clinical Oncology. The company said it achieved an accuracy rate of more than 90 percent across seven major cancer types and now plans to test the method in real-world programs.

Cancer specialists in Bengaluru who were not involved in the project voiced cautious optimism. "The study is promising, as an early signal," said Santhosh Kumar Devadas, head of oncology at Ramaiah Memorial Hospital. "But they need to do the study with a much larger group before we make any definitive conclusions." Neelesh Reddy, a senior consultant oncologist at Manipal Hospitals, told AFP that "only time will tell how this technology will be useful to the actual patients".

Which dog breeds are used to detect cancer?

India has described cancer as a major public health concern, saying one in nine of its 1.4 billion people are likely to develop the disease. Dognosis says it aims to improve "proactive and preventative medicine" while boosting "human-canine communication". Most of its dogs are beagles, along with some Malinois and Shepherd mixes, brought on board through adoption or legal breeders.

Only the best-performing dogs are selected, said Kulgod. The team lists each animal individually on the company website as an official "sniffer," alongside their photographs. All are given a strict work-life balance, with working time limited to around 30 to 45 minutes a day, he added.

How are the dogs trained to detect cancer samples?

At a facility called "Sniffspace," dogs test human samples on platforms fitted with automatic feeders that dispense treats. Co-founder Itamar Bitan, 28, who spent four years in an Israeli special-forces canine unit, said the dogs are trained using positive reinforcement to detect a "specific funky smell" in exchange for a reward.

"Some of the dogs run directly to the feeder expecting rewards, some dogs freeze, some dogs will scratch the sample with excitement," Bitan said. "But as long as the machine that learns how the dogs react to the sample is very consistent... we don't really mind."