Maybe you noticed it when you brought your dog to see another dog and the two circled around each other, sniffing, tails wagging, some of their hair maybe standing on end. Or maybe you noticed when your dog decided to greet you one day by sniffing your backside. Or perhaps you’re dog has been doing both. You just have to wonder, why do dogs feel the need to sniff not only each other, but everyone they meet?
The most common explanation is that sniffing each other is actually a dog’s way of saying ‘hello’. While this explanation is simple, there is much truth to it. While humans rely primarily on their sense of sight to recognize others, dogs rely on their sense of smell. If they are familiar with you, they don’t always need to get up close and smell you every time they see you, but if you are a stranger or you smell like someone else, they want to come closer and getting a better whiff of you to make sure.
With other dogs, they can determine many things from the smell of the dog. If they’re willing to sniff each other, they’re willing to start out on friendly terms. Much like how the human handshake was started in the middle ages as a sign of trust and a method of checking the other person for weapons. For most dogs, at least 33% of their brain is devoted to their sense of smell, compared to human’s 5% of brain power dedicated to processing smells and storing information.
Their noses are much more sensitive than ours, with some dogs’ sense of smell more than 10,000 times better than ours. They can tell the difference in smell between identical twins, follow an odor trail, and even smell emotions such as fear from other animals. So when they smell each other, they learn all kinds of information that we don’t notice. Smells can indicate the dog’s pack status, their mating availability, and health, among other things.
Their memory for smells is also very impressive. It is possible for a dog to recognize the scent of it’s mother despite being separated from them for years. So it may seem odd when they insist on smelling you every time they see you, but it will tell them where you have been, what you’ve been doing, and how you’ve been feeling. Though they could do this from farther away, in theory, it is similar to how humans will shake hands, hug or otherwise touch each other when meeting up, especially if it has been awhile since they have seen each other.
For dogs, the reasoning is similar: They want to be in contact. Since their sense of smell is their strongest sense, they prefer that to sense of touch (which is human’s strongest sense). This theory explains that dogs need to smell something any time there is a change in their enviornment. It is similar to how humans will often touch their belongings when returning from a long trip, or moving into a new house. It’s a comforting action, and their sense of smell, in these instances, fills in the functions of both our sense of touch and our sense of sight.
They do not recognize the other dog, or their human, by sight alone, but more by smell. So while we will often need to get close to our friends and loved ones and see them, dogs prefer to smell each other, as their eyesight is not their most trusted sense.
So the next time your dog is sniffing around where you don’t want it, don’t worry about it too much. It may be uncomfortable and you can discourage your dog from sticking his nose where it shouldn’t be, trying to stop them from smelling you in general can be disconcerting for the dog and could even cause them discomfort. Give them your hand to sniff or some other part of your body so they can recognize your scent. If it is a stranger to them, encourage the dog to sniff people’s hands. If it’s between dogs, don’t worry about it at all, getting in the way may even damage the dog’s relationship. If your dog is properly socialized and the other dog is as well, there will be no problems.
So next time you see your dog sniffing another dog or coming to greet you with his nose flaring, just remember that he’s saying hello and seeing how you’re doing.