Why Do Dogs Smell Armpits

Dogs have a wonderful sense of smell. Humans cannot even understand how many times more accurate a dog’s nose is compared to ours. Dogs can smell between 10,000 and 100,000 times better than we can. How much more could you learn about the world with that kind of ability? For example, imagine if you could record a person’s scent in your mind and memorize it forever. Like a unique, biological identification card, you could keep track of everyone in your life and know who’s coming before you even see them, you could even know what they have eaten and how they are feeling. That’s what dogs experience.

A dog’s nose is a powerful tool. They have as many as 300 million olfactory cells, compared to a human’s six million. In their brains, dogs have 40 times more cells for scent processing than humans have. They also have a unique ability to remember people and events by scent. A dog may not remember sound or sight the same way that humans do, but they still have the capacity to store impressions. Some smells may trigger associations even years after the initial exposure, especially those with intense emotions, such as fear. 

How do dogs use their powerful noses? First and foremost, smell is their primary method of gathering information. Like Facebook for dogs, their nose can tell them all they need to know about their environment, their humans, and any other animals (or their leavings) they come across. Some dogs have been trained to sniff out dangerous or illicit substances, like drugs or weapons, or certain cancers and diseases. It’s no wonder they enjoy sniffing out everyone and everything. Going on a walk around the block is a chance to find out how the neighbor’s dog is, whether there are any new animals in the area, any threats, and who’s been eating what.

Humans all have unique scents. Our scent isn’t only composed of the beauty products we use—everything from soap, deodorant, shampoo, and more—but also of our individual odor. When humans sweat, we smell. But it isn’t actually the sweat that stinks. The sweat is only an excretion of the apocrine gland, a special feature that produces pheromones. But the apocrine gland also produces bacteria that helps break down the sweat. And it’s not the actual sweat that smells, it’s the bacteria.

So what does all this mean? Dogs identify us by our unique scent, composed of the bacteria living on our bodies, the perfumes from products we use, and other unique biological information, including smells pertaining to stress, disease, and even hormones. The armpit and crotch are some of the best sources of olfactory information, and a dog will use whatever they can to learn more.

When dogs sniff around your armpit or nether region, they’re just looking for information and communicating in their own, unique way. It might be embarrassing, but for a dog, it’s commonplace and routine, like a handshake and “hello.” Don’t punish or yell at your dog for sniffing, it’s just a dog being a dog and doing what they do best. Some dogs may be more inclined to sniff than others. Gun dogs, like Spaniels or Retrievers, may be more sniff-focused than other breeds. Shorter-snouted dogs, like Pugs, tend to have a lesser capacity for smells than long-snouted dogs. It’s also not uncommon for your dog to seek out your scent while you’re away. They enjoy your particular aroma and may look for your worn clothes or bedding in your absence. Studies have shown that dogs will demonstrate positive emotional responses when confronted with the scents of familiar humans and slightly less so for familiar animals.

It’s important to let your dog exercise their need to sniff, especially on walks or trips. It might be irritating to stop every few seconds, so you can train your dog to move along with a short command, or distract them with a toy or another activity. If your dog is particularly insistent on sniffing out your guests thoroughly and invasively, you can also deter this by teaching your dog to sniff hands instead and reward them for staying calm.

Dogs will sniff often and thoroughly. Sometimes, they will sniff things we may find disgusting or embarrassing, but a dog has no such qualms. Things like a human’s crotch or another dog’s urine contains a wealth of information your dog can identify, distinguish, and even memorize. All dogs have a biological need to sniff, some more than others. As they age, dog’s sense of smell diminishes just like their other senses. And don’t ever punish your dog for using their nose; they won’t understand what they’re doing wrong and all you may do is create fear and anxiety, which can lead to aggression.

A dog’s nose is a miraculous organ. As we learn more about their sense of smell, we learn what potential they have to distinguish and identify specific scents. It is no wonder dogs are used as guides, aids, protectors, and even medical assistants. We may never truly know the extent of a dog’s capacity for scent. All they want to do is follow their nose, wherever it goes.