Meet the dogs helping scientists sniff out cancer

When rescue dog Chloe is not tumbling across the grass on a farm outside India’s tech capital, she is learning to sniff human breath for signs of cancer, with a little help from artificial intelligence.

Fitted with a 3D-printed helmet and harness packed with sensors, Chloe is part of an experimental effort to use dogs’ extraordinary sense of smell to develop a non-invasive test for the disease.

Research suggests dogs can be trained to detect cancer and other illnesses, from Parkinson’s disease to Covid-19. With this in mind, Bengaluru-based startup Dognosis is using AI to analyse dogs’ brain activity, breathing and body language, turning their reactions to scent into data.

“In an hour, they can do thousands of sniffs,” co-founder Akash Kulgod, 26, told AFP. “Each sniff can evaluate a sample.”

Early detection can make a crucial difference to cancer survival, but many patients in India are diagnosed only after the disease has advanced. Dog-based screening could potentially offer a simple first layer of testing, helping identify people who may need further checks.

Chloe, a Labrador mix, is one of 15 dogs being trained by the startup and fitted with customised data-gathering equipment. “It’s like a doggy ‘Iron Man’ suit,” said Kulgod, who studied cognitive science at the University of California, Berkeley.

A promising study

Research suggests disease can alter chemicals released by the body, creating distinctive odours. Dogs have around 300 million scent receptors, compared with about five million in humans.

A recent Dognosis study involving more than 1,500 participants across six hospitals in Karnataka state was published in the Journal of Clinical Oncology.

Their testing method was straightforward: each patient breathes into a cotton mask for about 10 minutes, after which it is sealed and taken to the lab. Patients do not meet the dogs.

The company said the method achieved more than 90% accuracy across seven major types of cancer, and now plans to test it in real-world programmes.

Cancer specialists 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, added that “only time will tell how this technology will be useful to the actual patients”.

A dog’s work-life balance

India has described cancer as a major public health concern, with an estimated one in nine of its 1.4 billion people likely to develop the disease.

Most of Dognosis’s dogs are beagles, alongside some Malinois and Shepherd mixes, but only the best candidates are selected. All have good “work-life balance”, with work limited to around 30 to 45 minutes a day.

At a centre called “Sniffspace”, the dogs test human samples on platforms fitted with automatic feeders that dispense treats as rewards.

Co-founder Itamar Bitan, 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”.

“Some of the dogs run directly to the feeder expecting rewards, some freeze, and some will scratch the sample with excitement,” the 28-year-old said.

“But as long as the machine that learns how the dogs react to the sample is very consistent, we don’t really mind.”

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