Why Dogs Sniff Butts: Butt Sniffing Explained

If you’ve ever been around dogs, you may be familiar with them intently sniffing at each other’s butts. You may have even been mildly embarrassed when a curious canine shoved their snout unceremoniously into your nether bits.

It’s an odd dog behavior, for sure. It may even seem unappealing to us humans, but whether we like it or not, butt sniffing is a very common canine behavior. So, why do dogs sniff butts? Let’s take a look at the reasons behind this perplexing canine trait.

The sense of scent – how dogs communicate

Before we can truly understand the canine compulsion for butt sniffing, we need to take a closer look at how dogs navigate and experience their world.

Like humans, dogs have five senses – hearing, taste, sight, touch, and smell. The sense of smell is arguably the most important of these to a dog given that their smell is far more sophisticated than our own.

Dogs have on average 150 million olfactory receptors in their noses (compared to 5 million in our paltry) which makes their sense of smell around 100,000 times more sensitive. With so much data collection happening in their nostrils, it’s no surprise that dog’s brain devotes around 30% of its mass to detecting and identifying smells.

Impressive stuff. But it’s not all. Dogs have a specialized organ called Jacobsen’s organ which is located in their snout, and which opens into their mouth behind their teeth. The purpose of this organ, also known as the vomeronasal organ, is to detect chemicals like pheromones and decode the messages that these pheromones are communicating.

Usually, this pheromone detection function relates to mating behavior. So, a male dog will pick up that a female dog is ready for breeding. It also helps puppies to locate their mother’s milk source.

So, what’s all this got to do with why dogs sniff butts? Quite a lot, actually.

Why do dogs smell each other’s butts?

When humans meet each other for the first time, they say a polite hello, maybe shake hands, and if they feel compelled to, they may begin to make polite conversation in which they will slowly get to know each other over a period of time.

Dogs, on the other hand, avoid all the time-consuming niceties and go straight to sniffing each other’s butts. This one small action will give them everything they need to know about their new friend.

How so? Well, that powerful canine nose is seeking out pheromones that communicate everything from reproductive readiness to health, sex, and diet in one sniff. These pheromones are scent markers produced by glands located – you guessed it – in a dog’s butt.

These anal glands produce a unique scent for each dog. With one sniff, dogs will know if they have encountered another dog before.

Generally, the more dominant dog will do the initial sniffing and will also end the encounter with a growl when he or she has had enough. A dog that prefers being a bit coy and not revealing too much will try to restrict their odors by covering their butt firmly with the tail or by sitting down.

Why do dogs sniff human private areas?

Dogs sniff each other’s butts as a friendly introduction in which they gain quite a bit of information about each other. Why, then, do dogs smell your crotch?

It all comes down to glands again. Apocrine glands, to be exact. These are a type of sweat gland found predominantly in the armpits and in the groin of humans. The sweat produced in these glands tends to have a stronger odor which of course attracts dogs with their super-keen sense of smell.

Why then do dogs sniff human private areas instead of their armpits?

Most people will use deodorant in their armpits to mask any odors produced here, so the scent here is mostly covered up. This makes the crotch a prime target for curious canine noses. Not to mention that human crotches are closer in height to doggie noses and much easier to reach.

How to stop a dog from sniffing human private areas?

Now that we better understand why dogs sniff human butts, what can you do to stop your dog from sniffing your crotch? It can be quite embarrassing when your dog shoves their nose into the crotch of every guest that comes to your home. Not just for you, but for all your guests. Is there a way to get your dog to stop sniffing the butts of your visitors?

The truth is that butt sniffing is a very normal part of dog life and you’ll probably never stop dogs sniffing butts. The least you can hope for is to try to distract them from the pursuit in some way.

Repeatedly redirecting your dog to greet people in a more appropriate way and then rewarding them with a treat will, over time, lead to a change in behavior but the primary drive for your dog to go in for good sniff will always be there. Training your dog to redirect their sniffing desires is probably the easiest way to circumvent your canine getting a reputation of a crotch sniffer.

Using your fist held out at your dog’s level, encourage your dog to touch your hand with their nose. Successful completion must be well rewarded with treats and praise. Using the command ‘touch’ to get your dog to touch your fist with their nose, you can redirect your dog’s snout away from groins to the relief of all those you encounter.

Of course, this kind of command will need to start at home first, with just you and your pooch. Then expand this to the rest of the household. Finally, when you’re confident that your dog is highly responsive to the ‘touch’ command, you can finally branch out to trying this in public, so your dog learns to respond to the command in every situation.

What to do when your dog is sniffing other dogs?

Dogs sniffing each other’s butts is entirely normal dog behavior and the best way for them to become familiar with each other. When your dog goes in for a sniff of a passing pooch, let it happen. There’s little use in scolding your dog and yanking on the lead to try to stop it.

In fact, if both dogs are healthy and well-socialized, it’s a good idea to let them sniff it out until they’re done. If one dog seems to be getting a bit carried away and you notice the body language of the other dog changing, it’s a good idea to break it up before it escalates.

Sometimes, problems may arise when two dominant dogs encounter one another, and neither is prepared to assume the less dominant position in the encounter. This can cause growling and aggressions and sometimes may lead to a fight.

If you’re concerned about the way your dog engages with other dogs in these settings, you can reach out to a trained behaviorist who can help you teach your dog an appropriate way of interacting with other dogs.

You can also train your dog well to respond to your sit or stay commands when you see the interactions going a little awry.

It’s highly unlikely that you will be able to stop your dog from sniffing butts entirely. It’s an instinctual and normal dog greeting behavior and usually isn’t problematic.

If your dog doesn’t sniff butts, you may be concerned. Sometimes it can happen because your dog is feeling a bit shy or insecure and isn’t interested in sharing information with other dogs.

It may be that your dog has had unpleasant encounters in the past and is now fearful around new dogs. Like humans, some dogs are shyer, and others are more sociable. Some dog species (like beagles and other hounds) are more active butt sniffers than other breeds.

If your dog goes from happily sniffing other dogs’ butts to suddenly not sniffing, it might be worth chatting to a vet. Your dog may be having issues with the sense of smell.

Final thoughts

Why do dogs sniff butts? It is s a form of greeting. It’s the canine equivalent of shaking hands with someone you’ve just been introduced to.

In the world of dogs, the sense of smell is extremely important, and much can be learned about a new acquaintance with a good sniff. It’s perfectly normal and natural for a canine to do this, and highly unlikely that a dog can be deterred from exploring its world using the keenest sense it has at its disposal.

There are ways to distract your dog from crotch-sniffing your guests or passersby on the street, but when it comes to encounters with another canine it’s best to let them sniff away if both parties are relaxed and comfortable.