Dogs can sniff out prostate cancer with 98 percent accuracy, found a study earlier this year that was presented at the 109th Annual Scientific Meeting of the American Urological Association.
Dogs have about 200 million olfactory cells in their noses, versus only 5 million in the human nose. Their keen sense of smell helps to explain the cancer-detecting feat.
Yet another study on dogs found that they can smell -- through a person's breath or sweat -- whether or not a diabetic person has high or low blood sugar.