HCR Update from Mark Sanna: There is no denying a dog's extraordinary sense of smell. While we have around 5 million olfactory cells in our noses - receptors that detect different odors - dogs have approximately 200 million. It is dogs' acute ability to trace scents that has made them so attractive to the medical world. A new study from Italian researchers, presented at the 109th Annual Scientific Meeting of the American Urological Association in Orlando, FL, found that specially trained dogs were able to detect prostate cancer from urine samples with 98% accuracy.