A team of physicians, veterinarians, and animal behaviorists at the University of California in Davis have been training a pair of dogs to identify the scent of cancer in humans.
The dogs are currently undergoing a 12-month training program to detect cancer in samples of saliva, breath, and urine. The dogs will learn to distinguish samples from cancer patients and healthy individuals, especially at the early stages of disease.
The theory behind the science is that the olfactory acuity of dogs enables them to detect odorant concentration levels at one to two parts per trillion, which is roughly 10,000 to 100,000 times that of a human. The researchers have established that dogs can recognize melanoma as well as bladder, lung, breast, and ovarian cancers, and the training can help the dogs identify the molecules that differentiate cancer from non-cancer.