Not only do dogs enrich the lives of their humans; they may also be trying to save our lives without us even realizing it! Dogs are detecting cancer; some are trained to do so, and others instinctually know something is not quite right.

Gill Lacey, who was featured on CBS's 60 Minutes in 2005, was saved by her Dalmatian, Trudi. Trudi began sniffing a tiny mole on Gill's leg. That mole was a malignant melanoma, which could have easily spread and put an early end to Gill's life, had it not been detected so early.

Just because your dog is intently sniffing you does not mean you should run with alarm to your doctor. A dog's nose is 10,000 to 100,000 times more sensitive than that of a human. A dog also has a larger portion of brain and nervous system devoted to the olfactory sense. Thus, a dog's interpretation of his surroundings is greatly affected by the information obtained from his nose. Sniffing you is telling your dog where you've been, who you met, what you ate, how you're feeling, etc.

However, if your dog seems consistently and considerably concerned about your body - beyond sniffing you to learn about your day – you may want to consider taking it seriously. He may be telling you something. Dogs can even smell cancer on your breath, particularly breast and lung cancer. One dog sat in her owner's lap, began sniffing and became very agitated. The dog alerted her owner to breast cancer this way – TWICE!

So, what are dog's detecting when they smell cancer? They smell a metabolic waste that is excreted by cancer cells, but not normal cells. It seems that some dogs naturally find this chemical to be a concern, or, at the least, interesting. Dogs can detect these chemical traces in the range of parts per trillion, making them able to smell cancer even during the early stages!

Dogs are currently being trained to detect cancer, similarly to how a dog is trained to detect drugs or bombs. A treat-based reward system is used, along with samples from healthy and cancer patients. The dog is rewarded when he sniffs the cancer sample. Eventually the dog learns to alert to the cancer sample by lying down or sitting when he comes upon it. Cancer-detecting dogs are often trained and capable in a matter of a couple weeks.

Studies around the world are proving that dogs can be extremely accurate in smelling and identifying cancer. This could be a huge benefit in the early detection of cancer, possibly saving countless lives. Researchers hope to incorporate dogs and their talented noses (literally the best odor detectors known to man) into physical exams in doctor's offices, alerting doctors to possible cancer concerns.

Think of all the things our best friend does for us – provide therapy, guide the blind, protect and serve those in law enforcement and the military, search for our missing loved ones, alert us to bombs, guard our homes, detect our cancer... provide unconditional love. Such an incredible creature.