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Why Do Dogs Sniff Butts?

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In the long line of seemingly weird dog behavior, perhaps no single act is as unusual to us as their habit of sniffing each other’s butts. While it’s not typical human behavior, sniffing butts is very common among dogs. In fact, wanting to sniff and allowing another dog to sniff are both signs of very well socialized canines.

But have you ever wondered: why do dogs sniff butts? Read on for more details on dogs sniffing butts and what makes it so tempting for our canine companions.

Is It Normal When Dogs Sniff Butts?

Yes, dogs sniffing butts is absolutely normal. Christine Pazdalski, a certified animal behaviorist and professional dog trainer based outside of Philadelphia, equates dogs sniffing each other’s butts to humans shaking hands.

“This is their greeting. It’s not only normal, but it’s good social skills when you’re a dog. It’s sort of what you’re supposed to do,” she says.

Not all dogs like to engage in this behavior, however. That doesn’t mean that something is wrong with them, Pazdalski explains. They just haven’t been socialized in such a way that they understand the meaning behind it.

“This behavior is not something that needs to be taught to dogs, but if it’s interrupted by a human when they’re young, a puppy may learn to not do it,” she says. “If dogs don’t practice it in a positive way, [they] can also learn to not accept rear-end sniffing from dogs.”

Why Do Dogs Sniff Butts?

If you continue with the handshake analogy, that behavior in humans dates back to a time when an extended hand literally meant to show that you were not carrying a weapon. That’s not exactly what canines mean when they sniff and allow sniffing, but it is a way to show a strange, new dog that they have nothing to fear.

Why do dogs sniff each other’s butts?

Dr. Leslie Sinn, a board certified veterinary behaviorist who works in private practice outside of Washington, D.C., says, “Dogs have a lot of scent glands around their tail and anal area that convey a lot of information. We don’t even know how much dogs can learn from doing this, but it’s a lot and includes the dog’s age, social status, if [they’re] reproductively active, if [they’re] physically in their prime, and what kind of condition [they’re] in.”

In this way, Sinn says it’s a related behavior to marking trees, buildings, telephone poles, and other similar objects with urine (and the sniffing you’ve experienced a million times when your dog stops you during a walk).

Why do dogs sniff human butts?

For all of the same reasons, you might find your dog coming up behind you to see what new things they can learn about you! It’s harmless enough, but that doesn’t mean you always want your dog doing this, especially to guests or anyone for whom behavior like this could be physically imposing (children, older individuals, or anyone else who might not be too sure on their feet).

Pazdalski says one great way to redirect this behavior when it comes to interactions with humans is to put your hand at your side with your palm up. “Dogs can gather as much information via scent from your palm as [they] can from the other parts,” she says. “When [they stop] sniffing your rear end and start at your palm, reward the change.”

Dogs will also do this to cats who live in the house, and while felines are also very scent-oriented animals, they won’t necessarily take too kindly to a cold nose in their behind, Sinn says. “Cats are never quite sure what to do with that because it’s just not a cat behavior, and they don’t find it too pleasing.”

She adds that many cats will tolerate the greeting initially, as long as the dog doesn’t run them over and continue to press the snout up the back end. “If the dog is inappropriate for too long, the cat may, at that point, sit down and swat him on the nose and cut off the greeting,” she says.

What to Do When Your Dog Sniffs Butts

There is a specific cadence to a butt-sniffing interaction that most dogs will follow, Sinn says, and as long as both do, there’s really nothing you need to worry about. Just let them sniff away.

“The dogs should approach from an angle and then circle,” she says. “The circling puts them nose to tail. That’s the way to control the interaction and diffuse any tension.” Dogs that approach head on and with unblinking eye contact are committing a sort of “social gaffe,” she adds, and that interaction could very well end up with snarls, snaps, and other forms of more aggressive body language.

Knowing if your dog is likely to tolerate and engage with this behavior appropriately is important, Pazdalski says, and she also always recommends that you work with your dog on verbal cues that will easily diffuse a potentially unwanted interaction. “The surefire way to prevent a bad situation is to have great recall, redirect, and get your dog’s attention back on you.”

Dogs Sniffing Butts: Other Tips and Advice

Because the behavior is associated with acquiring certain information about the dog whose butt is being sniffed, you might be wondering if dogs sniff the butts of other dogs they know well. Pazdalski says most of the time, they do not, but in cases where one of the dogs in a household goes out for a few hours and the other does not, the dogs may sniff upon being reunited to see if they can find something out about where they’ve been.

Additionally, dog sniffing, while a totally normal behavior under most circumstances, can become compulsive or excessive. “If there’s a dog who, for every dog they come in contact with, they rush him and pursue him relentlessly, that’s not appropriate behavior,” Sinn says.

The behavior should be pretty diplomatic and contained, she adds, so if those words don’t describe the way your dog exhibits it, it’s important for you to try to identify why. “You should be concerned about the dog being anxious or frustrated or overwhelmed in that situation such that they can’t dial it back,” she says. “The dog that is inflicting himself on others should be removed from that situation and given the opportunity to try to interact more appropriately in a different, quieter situation, instead of a dog park or on a busy street.”

No matter the context, if every interaction your dog has is characterized by that over-the-top behavior, Sinn recommends that dog parents strongly consider an anxiety evaluation by a certified professional.