Why Does My Dog Smell My Breath?

Why Does My Dog Smell My Breath?

It’s no secret that dogs love to sniff— you would too if you had a nose as powerful as theirs! But instead of just smelling flowers, dogs tend to seek out all sorts of strange scents. Dogs aren’t shy when it comes to smelling their favorite humans, and most dogs will gladly get a whiff of their owner’s breath.

What’s in our mouths that’s so interesting to dogs? Why do dogs smell our breath?

Your breath contains a lot of information about us that our dogs want to know! Your dog smells your breath to learn new things about you, like what you recently ate or your current health. There’s also a chance your dog is sniffing your mouth and face to greet you rather than smelling your breath.

This article will cover why exactly dogs enjoy smelling our breath as well as some of the interesting things they can detect.

Reason 1: Your Dog Is Just Curious (And Your Breath Smells Interesting)

Although humans and dogs may have a lot in common, we have different ways of learning about the world around us. While people gain information about their surroundings primarily through sight, your dog is able to learn all about its environment through smell.

This may seem strange until you realize that dogs have a sense of smell 10,000 to 100,000 times stronger than our own. With over 300 million smell receptors, massive portions of their brains dedicated to olfaction, and the ability to smell even when exhaling, it seems like dogs were simply made to be sniffing machines.

Your dog instinctively wants to use this important tool to discover information about everything around it, including you.

Reason 2: Your Dog Wants To Know What You Ate

While there’s a long list of reasons why your breath is so interesting to your dog, it should be no surprise that food and treats are one of the biggest motivators!

Dogs Can Smell Food Even Hours Later

Unless they’ve eaten a plateful of garlic or just drank a cup of strong coffee, most of us don’t know what others have eaten through smell alone. Your dog, on the other hand, can detect what you’ve eaten even hours after the fact.

With the ability to detect an odor as dilute as one to two parts per billion (that is, a teaspoon in two Olympic swimming pools,) your dog is equipped to smell trace particles from previous meals. Of course, you may be wondering why your dog cares what you ate.

Your Dog May Be Hoping For A Bite

An interesting study by animal behaviorists in 2009 gave surprising insight into why dogs tend to smell each other’s noses.

In it, dogs were paired up. One dog (the demonstrator) was allowed to search a nearby room for hidden treats. After they returned, the remaining dog (the observer) would typically greet them and smell their breath.

If the demonstrator had found food, the observer typically ran to the room they had been in to find more treats. If the demonstrator had not found any food, the observer was much less likely to search the other room.

In other words, the study showed that dogs sniff one another’s breath to get clues about where a nice treat might be! When your dog sniffs your breath, there’s a good chance they’re hoping you’ll share whatever yummy food they detect.

Reason 3: Your Dog Wants to Know About Your Health

But it isn’t just about food when it comes to your pup can learn a lot about your health just with a few sniffs of your breath.

Dogs Can Smell General Health

There is plenty that a single whiff can tell your dog about you. A person’s breath can reveal a surprising amount about their wellbeing, such as intestinal health and lung health.

This is due to the gases and Volatile Organic Compounds (VOCs) that we give off in our breath with all of the processes that go on in our bodies, such as gases given off by bacteria in our gut.

In a way, our breath can serve as an important marker for how we’re doing.

As a loving companion, of course your dog cares that you’re doing well!

Dogs Can Smell Disease

Exactly how strong a dog’s sniffer is varies from breed to breed, but every dog is equipped to smell otherwise often undetectable things.

Alongside more famous things such as specific chemicals or lost individuals, dogs are known to be able to detect a variety of diseases and disorders with better accuracy than many medical sensors.

Dogs are regularly used to detect things such as cancer, stomach ulcers, and possibly oncoming migraines. Some dogs are even trained to regularly smell their human’s breath for isoprene, a chemical that spikes when blood sugar is low!

The amazing video below shows a cancer-detection dog in action:

Of course, your dog wanting to sniff your breath or suddenly acting extra clingy isn’t necessarily a sign that you’re ill— your pup probably just wants to check in on you every now and then!

Reason 4: Your Dog Wants To Know Other Information About You

Even though detecting disease and learning more about your overall health was already impressive, that’s not all dogs can learn from just your breath.

Your Dog Wants to Learn About You

Believe it or not, your dog may be able to identify you by your breath alone! A person’s breath is as unique to them as their fingerprint due to their own special microbiome.

In addition to being able to identify you, your dog can learn many traits about you through your scent- even when it’s found on items other than you!

By detecting hormones and other chemicals, your dog can sniff out your age, diet, and even whether you are a male or female. If any of these traits are particularly interesting, it could explain why dogs find you so interesting!

Your Dog Can Learn About Your Mood

While your dog isn’t a mood ring by any stretch of the imagination, you may be surprised to learn how much a dog can know about how you are feeling by your scent alone.

Humans secrete various hormones and scents when they are happy, anxious, or angry, such as cortisol when stressed or adrenaline when scared.

Your dog is able to detect many of these hormones in your sweat and of course, your breath. By sniffing your breath, your dog is able to gain more information about how you are feeling or if you are stressed.

By smelling your breath, your dog is able to learn how you are feeling and how they should act toward you.

Reason 5: Your Dog Is Greeting You

After all this information of what your dog might be smelling in your breath, you may be surprised to learn there’s a chance your dog isn’t interested in your breath at all.

From barking to butt-sniffing, dogs can communicate with us in pretty cryptic ways. Face sniffing and licking are thankfully pretty straightforward— your dog is just respectfully saying hi!

Face-sniffing and nose-touching are common greetings for dogs. In wolves and wild dogs, this behavior is a way to express submission and is derived from how pups ask their mothers for food. Just as puppies tend to greet their mother with nose-touching and mouth sniffing, your dog may want to greet you.

After all, the face is quite interesting and it’s not just your breath. Some dogs may go from the breath to sniffing (and sometimes licking) their canine companion’s eyes or ears, too.

Should I Worry If My Dog Smells My Breath?

There’s rarely any cause for concern if your dog smells your breath. Usually, it’s just a sign that your dog is curious and comfortable. Although there have been instances of dogs detecting disease in their owners, breath smelling is considered perfectly normal behavior in dogs.

There is no need to dissuade your dog from smelling your breath either. It’s simply a way to learn about you and say hello!


It may seem strange at first that with such powerful noses, dogs would want to spend all day sniffing butts and breath. But as this article has shown, there are plenty of reasons your pup is so preoccupied with smelling their human and canine friends.

If your dog is smelling your breath, it is probably satisfying its curiosity and learning about you. There is also a chance your dog may actually be greeting you.

It’s hard for us to really relate to it since it’s all based around an extremely powerful sense of smell- something we don’t have. Not only does a dog’s powerful sense of smell encourage them to explore their breath, but it also means that can also smell things that we can’t begin to appreciate.

When it comes to detecting illness, this is extremely useful. But when it can also cause some confusion in the home as a dog’s powerful sense of smell can lead them to scratch at walls, roll in their food, and a long list of other strange canine behaviors.

No matter the cause, breath sniffing is normal, healthy behavior for dogs.

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