We already know dogs have great noses, but it turns out they're so great, they can even smell cancer.
In 1989, a London doctor wrote an article about a patient whose dog continually smelled a particular mole on her leg. That mole turned out to be early stage malignant melanoma.
Ever since then, researchers have been studying dogs' power to sniff out cancer. A group of researchers in the UK conducted an experiment using 3,000 urine samples from men with prostate cancer to determine how accurate the dogs' noses are.
The dogs were given eight samples to smell, one of which was from a patient with prostate cancer. If the dog correctly identified the cancerous sample, she would be rewarded. Previous smaller studies have estimated that dogs accurately detect cancer 90 percent of the time.
A dog's nose is a powerful tool. It has 300 million sensors, while human noses only have a measly 5 million. The part of a dog's brain that analyzes smell is also about 40 times bigger than the part of the human brain devoted to smell.
Scientists still are not sure exactly what the dogs are smelling in the samples, though they think it must be volatile chemicals which are only given off by cancerous cells, not healthy ones. Dogs' noses are so powerful, that they can even detect the scent when the cancer is at stage zero.
With such a powerful nose, your best friend might be able to save your life.