The Smell Test: Why Dogs Sniff Butts

Question: What’s the most popular activity at every dog park in existence? If you said fetching, chasing, or wrestling, we have to wonder whether you’ve actually visited a dog park yourself. Also, you have a strange habit of not reading article headlines.

Butt sniffing was the answer we were looking for.

Upon entering a dog park on a nice day, you’re likely to find yourself surrounded by several (or more) dogs. Being a dog person, your first instinct might be to pet them. However, in many cases the dogs are less interested in a stranger’s affection and more interested in your dog – or more specifically, your dog’s butt.

Small dog smelling larger dog's butt
This is terribly interesting stuff if you’re a dog.

What’s That Smell?

Dogs may be man’s best friend, but there are some things about them we will never understand. That’s because dogs and people perceive the world in very different ways.

For humans, smell is a second-tier sense that we use to enjoy food and horribly artificial air fresheners.

For a dog, smell is the dominant sense – it rules their world in a way we humans and our puny olfactory abilities simply can’t comprehend.

When a dog smells another dog’s bum, he’s going to the best (and stinkiest) source of information. Like many animals, dogs have anal glands in their rectums. These glands produce a fluid that uniquely identifies the dog and holds other key tidbits of information about what he or she has been up to lately.

Canine Social Networking

Some people have compared butt sniffing in dogs to saying “hi” or shaking hands, but it actually goes much deeper than that. A dog’s anal glands can reveal its gender, reproductive status, general health, and even what it had for breakfast.

In other words, it’s like peeking at someone’s Facebook page before you meet them.

Two dogs in a mutual butt sniffing circle
Mutual butt sniffing. Image: Tim Dorr via Flickr.

Scent can also reveal whether the dog is friendly, nervous or hostile – which are obviously important things to know when two dogs meet for the first time.

But just as important is the butt sniffing ritual itself. How dogs conduct themselves when sniffing and being sniffed is key to harmonious canine relationships. That’s why you should let dogs sniff away when greeting each other, regardless of how distasteful it might seem.

Long-Term Sniffing Relationships

Of course, sniffing isn’t just reserved for introductions. Dogs who live together may sniff each other’s butts regularly throughout their lives. It’s a way of checking in and reinforcing social bonds.

At one time or another, your dog may even attempt to sniff your patootie to see what’s up. Corgi owners don’t have to worry too much about this (except under very unusual circumstances), but it’s a fairly common complaint among people with long-legged dogs.

If it really bothers you, you can often correct the behavior using standard dog training techniques. Otherwise, just take it as a compliment – your dog thinks you’re one of the pack!