On my walk today with my dog, my dog's nose was working overtime. He held it to the ground like aardvark rooting out every single smell in the side lawns on the way to the park. I began to wonder just how much information he must be able to take in through the nose so I did a little research online tonight.
A dog has anywhere from 1000 times to 1,000,000 times better smell than a human. Dogs have about 60 times more spongy tissue and nerves in their nose than humans do. Some breeds can smell better than others with Bloodhounds leading the pack, although German Shepherds also have a keen sense of smell. Dogs are also much better at identifying smells than are humans. In fact, a dog can sniff a bare sidewalk and identify everything that has pass along that day.
Dogs have such an acute sense of smell they can be trained to detect gas leaks in pipes that are dozens of feet underground. They can detect termite infestations. Dogs can also smell diseases such as cancer and they can detect by smell when someone is about to have an epileptic fit. Some dogs have been specially trained to make sure a person who is about to have a seizure is in a safe place and some even know how to push an emergency button before it happens. I have a great deal of respect for dogs and their superior sense of smell. They are truly amazing!