What Causes Puppy Breath + What Does it Smell Like?

what causes puppy breath

Young dogs have very particular smelling breath, so much so that it has its own name; puppy breath. But despite what you might think, puppy breath doesn’t always mean bad breath. It can also refer to a sweet smelling aroma or even what’s been described as smells similar to skunk.

In this guide I will explain all I know about the causes for puppy breath, and what the smell has been described as being like. Here are the short answers first, with more detailed information further down the page.

What causes puppy breath? Some vets claim that puppy breath is caused by their milk only diet as newborns. The natural sugars can then break down in their digestive system to create the sweet-smelling puppy breath people refer to.

What does puppy breath smell like? Puppy breath can smell oddly sweet due to their diets. They also don’t have any tooth decay at this age, so puppy breath can smell better. But some puppies do get bad breath, or breath often compared to the smell of skunk.

There’s so much more to it than this though. Read on for more details on why puppy smells this way, more details on the causes, and what do you do if their breath suddenly takes a turn for the worse?

What causes puppy breath smell?

The origins and causes of the puppy breath smell are not entirely clear or always agreed upon. We all know that a whiff of adult dog breath is no fun at all. It isn’t usually offensive but certainly not sweet.

Many vets claim that the characteristic sweetness of puppy breath is caused by their milk-only diet that puppies have when they are so young. The enzymes in milk are complex sugars that break down in our digestive system.

Therefore, the odor that the puppy breath smells like is often compared to a sweetish, milk-like scent.

what does puppy breath smell like
Puppy breath can smell like many different things when you get up close.

On the other hand, some vets think puppy breath is caused because the puppy is so young. New teeth and fresh oral hygiene keep your puppy’s mouth smelling clean…because it is clean.

It is the cleanest it will ever be in their entire lives!

Compare this with older dogs who are much more susceptible to dental issues and gum disease that can cause bad breath. Senior dogs are the most vulnerable in this way so the theory that dog breath gets worse with age makes a lot of sense.

Following on from the age theory, it has been suggested that the gut flora and bacteria in puppies are different than that of adults.

You know the “good gut bacteria” being sold to you in yogurt ads? That’s what we are talking about here.

The gut bacteria present in young puppy bellies give off a sweeter odor than that of older dogs.

That said, there is no definitive theory as to why puppy breath happens. All of these are equally credible and don’t negate one another.

The sugary odor that puppy breath smells like tends to end when your puppy is around 8 to 10 weeks old, so enjoy it while it lasts!

What causes my puppy to have bad breath?

Okay, so we’ve talked about the strange phenomenon that is sweet puppy breath.

What if your puppy has bad breath? What could be the causes? Here’s the short answer first again, then more detail.

What causes my puppy’s bad breath? Puppies get bad breath due to injured gums, food stuck in their teeth, or in more serious cases due to a bigger health issue. Bad breath in puppies can be caused by problems such as kidney failure.

Puppies notoriously put a whole manner of things in their mouths so, like my puppy, there is a chance a piece of food or other item has gotten stuck in their gums. Inflamed or injured gums can lead to gum disease which causes very severe halitosis.

Indigestion can cause bad breath, but you would be able to spot this with its other accompanying symptoms of diarrhea, gassiness, and vomiting.

More serious health issues like kidney failure can result in strange oral odor. Of course, this is the rarest, but you should be attuned to changes in your dog’s breath.

The final common cause of bad breath in puppies is their annoying tendency to eat poop.

Yes, puppies are huge fans of this for some reason!

Thankfully they grow out of it during adulthood. You need to keep a watchful eye on them during the housetraining stage to prevent them from making a habit of eating their own stools.

As soon as they have relieved themselves, clean it up, and keep them away from it. Literally eating poop is a surefire way of having breath that smells like poop!

Handy Hint: If you notice your older dog has breath that smells like metal, it could be the sign of a health issue such as kidney failure.

Should I brush my puppy’s teeth to help bad breath?

Brushing your puppy’s teeth certainly has its benefits – one of which is prevent bad breath!

It is a good way to inspect your dog’s mouth for any strange bodies, cavities, or cracked teeth. It also staves away gum disease and dental issues, leading to maintained pearly whites and fresher breath.

Many vets suggest that you should work up to brushing your dog’s teeth daily. Starting this practice in puppyhood is a great way to start. They won’t love the process – and neither will you probably – but you’ll grow accustomed to it over time.

Now, I’m not saying to whip out the crest and your old toothbrush and attempt to achieve minty freshness with your dog. There are specific toothbrushes and toothpaste formulated for dogs.

Some are even bacon-flavored to make the whole ordeal more bearable. My dogs prefer the finger brush technique, which is when you put a rubber toothbrush-like cap on your index finger and gently rub on your dog’s teeth and gums.

Doggy toothpaste doesn’t tend to suds up. You can allow them to lick it off their teeth afterward – don’t rinse off all your hard work!

Beyond brushing, there are certain chew toys that are recommended for maintaining your dog’s teeth. Toys and rubber chew toys are perfect for this purpose.

Puppy teething 101

Just like human babies, puppies teethe as their baby and adult teeth are coming through. Your puppy isn’t only destroying your furniture for fun, but also to soothe their gums.

If you have ever had a wisdom tooth come through, you know how uncomfortable it is to grow new teeth.

Your puppy’s first set of teeth will come through when they are around 4 weeks old, leading to a full set of adorable baby puppy teeth by the time they are 8 weeks old. During this time, they can suffer with puppy teething bad breath.

4 to 5 months later, they are fast transitioning into adulthood so their baby teeth will start to fall out. You’ll find them lying around the house in the most inconvenient of places!

It takes around 2 months for the adult set of dog teeth to poke through.

To help soothe your puppy’s aching gums during this time, it is good practice to introduce soft chew toys. My puppy’s favorite was the Kong, as they are soft on gums. As soon as she was able to destroy it with one bite, we knew her adult teeth were fully set and it’s time to upgrade.

It is a great idea to have a vet check your dog’s teeth and gum health after their adult teeth have grown in. This helps spot any potential issues they may have before they become more serious.

Handy Hint: If your puppy is breathing hard or fast in their sleep it’s usually nothing to be concerned about. However, it is worth reading this checklist for any serious signs that might require expert help.

When to involve the vet with puppy breath

The best thing to do is to figure out the cause of your puppy’s bad breath before going to the vet. For example, if you have seen your dog eat poop and then complain that their breath smells bad, your vet isn’t going to give you any groundbreaking advice here!

Poopy breath is as poopy breath does.

If you’re also maintaining your dog’s oral hygiene by brushing and a good diet, then there should be no issues.

It’s when puppy bad breath continues despite your best efforts to keep your dog’s mouth clean, or if there is a sudden change.

If you notice a crack in your puppy’s tooth or a stuck piece of food, it is best to contact the vet for help.

Kidney disease can cause urine smelling breath. Diabetes can cause sweet-smelling breath (past the puppy stage). Liver disease causes really bad breath that you can smell from across the room.

Note the signs and other symptoms to help your vet diagnose the problem.


Let’s agree that smelling anyone’s breath, especially your dog’s, is not anyone’s favorite pastime. As dog owners, however, it’s our duty to do the unpleasant thing. Smelling breath, tending wounds, and checking poop are all part of our regular routine to maintain the health of our dogs.

It was only from sniffing my Retriever puppy’s foul breath that I discovered she had a stick lodged in the ridges at the top of her mouth.

Who knows how long it had been there or how it got there!

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I’ve also prepared some other guides for puppy owners in those first few weeks and months.

Image in header via https://pixabay.com/photos/dog-puppy-abb-bastard-muzzle-eyes-2281453/

Marc Aaron

I write about the things we've learned about owning dogs, the adventures we have, and any advice and tips we've picked up along the way.

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