By harnessing the power of the canine nose, humans have used dogs to successfully detect everything from lost children to diseases such as cancer. Here’s how, when it comes to your dog, it is often the nose that knows.

While you have only five million scent receptors in your nose, your dog, depending on the breed or mix, has around 200 million scent receptors. And, almost everything about the shape and structure of your dog’s nose is geared towards getting maximum use out of those scent receptors.

Notice your dog’s wet nose and how his nostrils seem to flex or move. The moisture on your dog’s nose is caused by secretions from mucous glands in the nasal cavity, and it helps your dog trap odor molecules. His somewhat flexible nostrils – he can even move one nostril at a time – not only allow him to detect where a scent is coming from, but because each nostril can expand to open wider, he is able to maximize the number of scent molecules entering his nose with each sniff.

Inside your dog’s nose is a shelf-like area that allows your dog to collect and accumulate odor molecules. The shape of the shelf traps odor molecules, and when your dog breathes his breath passes under the shelf without disturbing the shelf’s scent “contents.” The scent molecules are then processed by two olfactory bulbs in your dog’s brain. Whereas your brain’s olfactory bulbs weigh only about .5 ounces, your dog’s olfactory bulbs weigh 2 ounces. Combine this with the fact that your brain is about ten times larger in total than your dog’s, and we can say that your dog devotes nearly 40 times more of its brain to scent than you do.

All of your dog’s enhanced scenting equipment not only allows him to smell things that are too faint for you to pick up on, but also allows him to separate the multiple layers within each scent. For example, you smell a lasagna you are baking in your oven. Your dog smells each type of cheese you have used, each spice, and the flour in the pasta.

So, that cold wet nose in your face each morning?  That's the nose that knows.

Does a warm & dry nose mean your dog is sick?  To find out click here!