Sniffing the bushes and grass for dogs is like their social media. Dogs have approximately 125 million to 300 million scent glands depending on the breed. Compared to our 5 million scent glands as humans, the difference is enormous. Dogs can smell separately through each nostril. Their moist spongy nose helps capture any scent that a breeze carries in each breath of fresh air. The olfactory system in the brain of a dog is many times larger in dogs than in humans too. When dogs take a breath, most of the air goes into their lungs but a portion goes into a space that humans do not have known as the olfactory recess. There, the air can collect and swirl through an intricate maze of passages. When they exhale, they exhale air through little slits on the sides of their nose so each breath gives them a fresh whiff of scents.
Dogs can tell where we have been and who we have been with as soon as we enter the room. The dogs that I walk regularly can always tell when I have been with a new client. They give me a knowing longer sniff. They check my shoes and pant legs. They always know. It is remarkable. Dogs can smell hormones produced by emotions like sadness, anger, fear, and happiness. For this reason, many think that dogs can actually tell if a person is "bad" because they can smell the anger, fear, and distress hormones. Smelling fear doesn't make them aggressive though, it makes them afraid too and increases their level of stress. Smelling happy hormones makes dogs happier too.
This is why dogs are generally so happy to explore new surroundings. They smell so much more than we do! Sniffing around the neighborhood is how dogs catch up on all the local news. They can tell who has been in the yard and even if the other dogs are sick. Dogs can tell if we are sick too. Dogs can be trained to detect, diabetes and cancer.
Reviewing all this information is mentally tiring to dogs and is just as important as the physical aspect of a good walk for dogs. This is especially helpful with puppies that are still learning about their world and need to be tired out. The smarter the dog, the more important it is to mentally stimulate them. This is important to remember the next time you take your dog for a walk and get frustrated because they want to smell every bush and tree trunk.
If you have an athletic dog and want to make sure they’re tired, be sure to include some slower sniffing time for their brain. Smell (and nose work) is a wonderful way to do that. There are lots of games you can play with your dog with simple things like muffin tins, toys, and treats hidden under the toys in a muffin tin. This is a fun rainy day game for dogs and puppies. A dog that gets mental and physical exercise is calmer and happier. You’re couch and shoes will thank you.