Why Do Dogs Sniff Butts?

Let’s be honest, we’ve all seen two dogs become acquainted before. It starts off cute, maybe a sniff here or a lick there. But then it become a bit more awkward to watch. One of the more unorthodox habits of dogs is – yep, you guessed it – sniffing each other’s butts. While this behavior seems odd and even a little gross to humans, it actually serves an important part in the way dogs communicate with one another.

It’s no secret that dogs have a spectacular sense of smell. But their noses are not the only way dogs can pick up and process different scents. Behind the upper incisors and inside of the nasal cavity lies something called Jacobson’s organ. Jacobson’s organ is essentially a second olfactory system that’s specifically used for chemical communication. This organ picks up on substances that have no smell at all, allowing dogs to detect the undetectable.

Via Jacobson’s organ, dogs are able to smell chemical and biological differences of other dogs. By sniffing, dogs can learn another’s sex, mood, health, and even what they recently ate. The reason dogs sniff butts, though, is because of the smell of another dog’s anal glands. These glands secrete an odor that human’s usually can’t smell because it’s masked by the smell of feces. Dogs, on the other hand, can look right past this.

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Each dog’s anal glands produce a smell unique to that dog. These smells can act as an identifier for other dogs to determine important information about them, such as whether or not the dog is friendly, what sex they are, if they are available to mate with, and more. Cool, right?

Aside from the smell of each dog’s anal glands, sniffing each other’s butts can also be a display of dominance. Some dogs (almost always the dominant) may growl to keep dogs from sniffing them, and some may simply sit down so the other can’t gather much information about them.


Overall, dog’s butts are the key to dogs understanding each other. While this may seem weird to humans, it’s best to think of it as a doggie handshake or hug upon first meeting. It’s a way to understand important information quickly in order to protect your dog. Who knew butts could be so informational?

Abigail Kurten
Author: Abigail Kurten

Hi! My name's Abigail, and I intern as a Content Writer for DogFriendly.com. I have one dog, a chocolate lab named Riley who's the best! My favorite breed of dog is a Bulldog or Saint Bernard, though.

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