Can Dogs Detect Cancer?

Every year, more than 1.7 million new cases of cancer are diagnosed in the United States. According to the National Cancer Institute, over 38% of men and women will be diagnosed with cancer at some point during their lives. Cancer is one of the leading causes of death worldwide and scientists are constantly working on ways to detect it in the early stages when it is still treatable.

Though cancer screenings have progressed by leaps and bounds, it is the more unconventional screening methods that are the most impressive. One of the most impressive cancer detection methods might be right under your nose or, more specifically, your dog’s nose. Keep reading to learn more about whether dogs can detect cancer.

Related: Dog Detects Early-Stage Lung Cancer With Incredible Accuracy

You already know that your dog’s sense of smell is stronger than your own, but do you know just how strong your dog’s nose really is? Your dog has the ability to pick out the subtlest of scents, filtering them out from all of the other smells around it. To put it in numeric terms, your dog smells in parts per trillion – that’s the equivalent of a drop of blood in 20 Olympic-sized swimming pools.

Your dog’s sense of smell is 50,000 times as strong as yours. When you walk into a room, the first thing you do to get your bearings is look around. The first thing your dog does when he enters a room is take a good whiff, picking out all of the individual smells. Your dog’s nose is extremely complex and has the ability to process scents in a unique way. Each nostril can smell independently of the other and your dog’s brain puts together those myriad smells into a 3-D picture in the dog’s brain.

Related: How Strong is a Dog’s Nose?

It makes sense that your dog can follow the scent of a prey animal and that he can tell from the other room when you open a bag of chips. But how do dogs detect cancer?

Dogs can be trained to sniff out everything from explosives to drugs. Though scientists don’t fully understand what a dog is picking up when he detects cancer, dogs have been trained to detect cancer in urine and breath samples. One example is a study using 5 dogs – two Portuguese Water Dogs and three Labradors – who were trained to detect breast and lung cancer. The dogs were asked to smell samples from 169 individuals, 86 of whom had cancer. The results? All five dogs accurately identified the samples from the cancer patients.

The tricky part about training a dog to detect cancer is targeting the specific scent you want the dog to identify. Cancer scent is a complex combination of thousands of particulars that are completely unique to each person. It takes hundreds of samples or more for the dog to learn to detect healthy breath and to be able to differentiate it from the scent of cancer.

Though there are plenty of amazing stories about cancer-detecting dogs, there is still a great deal to be learned about how dogs do it and whether this ability can be harnessed for medical purposes. Time will tell whether man’s best friend has any true cancer-detecting potential.