Simple Reasons Why Puppy Breath Smells Like Fish

Why does my puppy’s breath smell like fish? Teething is one of the most common reasons why a puppy’s breath can smell like fish since puppies aren’t born with teeth. Always check to make sure that your puppy’s baby teeth aren’t trapped along the gum line between the emerging permanent teeth.

puppy breath smells like fish
Puppy Breath Smells Like Fish

Bad breath is one of the most common complaints dog owners have, and the fact that it can be caused by a variety of factors is often frustrating.

In adult dogs, the most common cause of bad breath is dental issues, but if your puppy has bad breath, especially breath that smells like fish, you might feel at a loss.

So if you find yourself searching, “puppy breath smells like fish,” you are probably in need of a solid answer to your burning question, and we have that answer. Keep reading to find out the reason for the smell and for some tips on how to deal with it.

Pet owner looking not good with the smell of her dog's mouth

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Related Reading: What Causes Dogs to Smell Like Fish?

Why Does My Puppy Breath Smell Like Fish?

Here are some of the common reasons why your puppy’s breath may smell like fish.


Puppy teething is the most common culprit for bad breath in puppies. These little doggies lose and regrow teeth, just like humans do. You may notice that the teeth of an extremely young pup are small and sharp.

If you’ve accidentally found yourself at the receiving end of a playful bite, you may have been surprised to find that it can hurt quite a bit.

These sharp teeth are the equivalent of baby teeth in humans—they are designed to fall out and be replaced by duller, larger, permanent teeth. Ever wonder why your puppy seems determined to chew on everything they can get their mouth on?

It feels good on their teeth, which are probably a bit painful and loose. The good news, therefore, is that there is nothing wrong with your puppy. Stinky as it is, the smell is perfectly normal and will pass as your dog matures and grows his permanent teeth.

Teething is by far the most likely culprit of your puppy’s fishy breath, but what if you know that’s not the answer? What if, perhaps, your doggie has already been through its teething period? There are a few other factors that might help explain it.


Does your puppy seem to have a taste for feces? Gross as it sounds, puppies are curious creatures, and most of them are willing to try anything once (oftentimes more than once, unfortunately). Coprophagia means “feces-eating”.

Just like humans, what a dog eats can greatly impact their breath. So if they’ve been feasting on feces, there’s a good chance their mouth won’t smell delightful. Most coprophagic puppies outgrow the phase, but for now, you should focus on preventing your doggie from getting into their own poop, or the poop of other animals.

You can do this by supervising your doggie when they go outside and immediately pick up and throw away what they “leave behind”. If your doggie has an accident indoors, make sure you’re prepared to clean it up immediately—don’t wait until a later, more convenient time and leave your doggie to ingest it. On walks, keep them on a tight leash and pull them away if they begin sniffing the feces of another dog or wild animal.

Fishy Food?

Believe it or not, some dog foods can cause bad breath (like how fish oil supplements can give us “fish burps). If you suspect your doggie’s food is the culprit of your puppy’s fishy breath, try switching to a different brand and see if the problem resolves itself. If not, it’s likely that something else is actually causing your dog’s mouth to stink.

Puppy Mischief

Remember what we said about curious puppies often eating their own feces? Well, it turns out that they sometimes eat other disgusting specimens as well. If you let your puppy out unattended to do their business, there’s a good chance they might be getting into something rotten that they shouldn’t be.

Luckily, this problem is easily solved by keeping a close watch on your doggie while they’re outside or accompanying them when you let them out.

Anal Sacs

Your dog’s anal sacs are the reason other dogs sniff their butt when they want to get to know them—they produce a powerful smell and are actually helpful for potential doggie friends who want to know whether or not they’re dangerous, what their gender is, and even what their diet consists of.

The sacs are usually emptied when your dog does a #2, but occasionally they don’t empty properly and instead fill up, meaning that when your puppy licks their butt, that smell is transferred to their mouth. Yuck!

If your puppy’s bad breath is accompanied by a lot of scooting his butt across the floor, it’s likely that their anal sacs are full. A vet can easily squeeze them for you, leading to more comfort for your pet and hopefully less stench for you.

Tips For Dealing With Your Puppy’s Fishy Breath Smell

Unless you’ve identified another cause, your puppy is probably just teething. Now you know it’s normal, but that doesn’t make it any less stinky, and it essentially leaves you with two options—ignore it or take measures to prevent it.

If you decide you simply cannot stand that fishy puppy breath, there are a couple of easy ways to fight the stench.

Coconut Oil

One pet parent recommends rubbing a bit of coconut oil on your puppy’s gums to ease the smell. Apparently, dogs really enjoy the taste of coconut oil too!

Brush their teeth

Using a bit of baking soda to brush your pup’s teeth can go a long way. Baking soda helps to remove plaque and bacteria—two things that can make bad breath more potent—from your dog’s teeth.

They likely won’t like this one as much as the coconut oil, but it can help set a precedent and establish a routine for when they are older. After all, permanent teeth will require regular cleaning if one is to avoid dental problems later.

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Lovely interaction of pet owner carrying her dog
Pet owner carrying her dog

Final Thoughts

This video contains some additional suggestions for fighting bad breath.

Now you have a list of possible reasons why your puppy’s breath smells like fish. The most important thing to watch out for, however, is whether or not your puppy continues to have bad breath after they finish teething.

If the stench persists into their adult years, we recommend taking them to a vet. The vet will most likely take a look at their teeth and recommend a dental cleaning session to remove bacteria and prevent tooth decay. Your dog might also need some teeth extracted.

stuart and his dog

Family Dog Expert Author

Hi there! I’m Stuart, a devoted dog lover and family dog expert with over a decade of experience working with our furry companions. My passion for dogs drives me to share my knowledge and expertise, helping families build strong, loving bonds with their four-legged friends. When I’m not writing for SirDoggie, you’ll find me hiking, playing with my beautiful dog, or studying music.