Why Do Dogs Smell Your Crotch?

Updated Aug. 30, 2023

Dogs can find lots of ways to embarrass us with their behavior—from digging our underwear out of the hamper to display for guests to barking incessantly at neighbors slowly making their way along the sidewalk in front of our house.

But no behavior is quite as awkward as when a dog greets a friend or stranger with an aggressive crotch sniff. Is your dog just ill-mannered? What information are they getting from smelling someone’s crotch?

Here’s an explanation of why dogs do this and whether you can do anything to stop the behavior.

Is It Normal for Dogs to Sniff Someone's Crotch?

It turns out that when dogs do this, they are just using their keenest sense, smell, to gather as much information as possible about their new friend.

A dog’s superpower-level sense of smell explains why it is totally normal for dogs to want an extra-close smell of our nether regions. Dogs possess up to 125-250 million olfactory (scent) receptors in their noses, compared to about 5-6 million of those receptors in humans.

The part of a dog's brain that is devoted to analyzing smells (the olfactory cortex) is about 40 times greater than ours. Their sense of smell is powerful enough to detect substances at concentrations of one part per trillion—that’s a single drop of liquid in 20 Olympic-size swimming pools!

Part of this amazing ability comes from a second olfactory system in a dog’s nasal cavity called the vomeronasal organ (or Jacobson’s organ). This organ helps dogs pick up on scents that are not detectable to humans, such as the smell of their mother for a nursing pup or the pheromones of a female dog in heat. Dogs use their sense of smell to learn about the world around them and, like it or not, our crotches are a smorgasbord of scent.

Why Do Dogs Smell People's Crotches (Instead of Other Body Parts)?

While dogs are driven to smell everything around them, apocrine glands are to blame for their obsession with certain areas of our bodies. Apocrine glands are a type of sweat gland that, in humans, are found in areas with hair, predominately the armpits and groin.

These glands produce a high-protein sweat, and when it’s mixed with the natural bacteria on our skin, it creates body odor. Apocrine glands produce strongly scented sweat even when we’re clean, so it’s no surprise that a dog’s nose can pick up on the smell, especially in people they don’t live with every day. 

Many people use deodorant and/or antiperspirant products to prevent odor in their armpits, which means dogs are more inclined to sniff the crotch area instead.

Is It the Same as Dogs Smelling Other Dogs' Crotches or Rear Ends?

While the highest concentration of human apocrine glands are in our groins and armpits, dogs have apocrine glands all over their bodies, thanks to their (comparatively) hairy skin. So, if these odor-producing glands exist everywhere on a dog, why do dogs go out of their way to smell another dog’s rear end?

The answer is found in two tiny sacs tucked into a dog’s rectum that you may know as anal glands. Anal glands produce a fetid-smelling substance that is expressed into the rectum each time a dog passes stool, but it can also be secreted during times of stress or excitement.

The odor of anal gland secretions is unique to every dog and can help dogs remember if they’ve met before. Even if they are old friends, the distinct smell of anal gland secretions can communicate important information, like where a dog has been and what they’ve been eating.

How to Prevent a Dog From Sniffing People's Crotches

One of the best ways to keep a dog from doing any unwanted behavior is to train them to perform another task instead.

To keep your dog from being labeled a rude crotch sniffer, dog trainer Victoria Schade, CPDT-KA, suggests teaching your dog to “target” your fist. She says that targeting is one of the easiest tricks to teach because it uses a dog’s natural inclination to explore with their nose.

Schade recommends these steps:

  1. Present a fist to your dog at their level.

  2. When they move toward it, reward the behavior with a dog-training clicker or by praising your dog with a word like “good!”

  3. Give your dog a high-value reward from the other hand.

Work up to your dog actually touching their nose to your fist when you present it, and then attach a word to the behavior. You can use a word like “touch” or “target,” or get creative and use something like “bump it.”

Teaching your dog to target a fist is helpful in a crotch-sniffing situation because you can hold your fist in a number of positions around the body that keep your dog away from the groin area.

Once your dog has mastered this behavior at home (with you and everyone in your household), teach them to respond to this request in public, as well. Enlist help from friends to get your dog to respond to the cue when meeting new people, too.

The more people and situations in which your dog learns to “bump it,” the less you have to worry about the embarrassment of having a crotch-sniffing canine!

Featured Image: istock.com/CBCK-Christine

Kasey Stopp, DVM, CVA


Kasey Stopp, DVM, CVA


Dr. Kasey Stopp was born in rural Illinois but spent most of her life in Cincinnati, Ohio. She attended the University of Cincinnati where...

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