Why your Dog is Foaming at the Mouth & What to Do..

Last Updated: April 16, 2023

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We've all hear those adages about dogs foaming in the mouth. While the theatrics associated with the sight might have been true in the past, things are a lot different now.

Domesticated dogs are healthier than ever! Thanks to modern veterinary medicine, running into an aggressive frothy-mouthed pooch isn't so common anymore.

So, what does it mean when you see foam developing in your dog's mouth?

dog foaming at the mouth

Mouth foam is not as rare as most people think. Many factors can cause it. Some reasons are innocent enough. But even still, seeing your dog foaming at the mouth is not something you should ignore.

What Exactly is this Foam?

Before we get into the potential causes of a foaming mouth, let's figure out what's actually going on. When foam develops in the mouth, it's usually nothing more than a mixture of saliva and air.

The combination of panting and excessive drooling result in a thick mixture. If you look closely, you may even see larger bubbles floating around in that sticky mess. The foam is a form of hypersalivation.

Now, there's a marked difference between standard drooling and foaming. Understanding that distinction is important when trying to determine the root cause.

Also read: Dog Dry Heaving? Try One of These Remedies

Drooling appears as teardrops that hang from the sides of your dog's mouth. You might see it hanging from their mouth whenever they open wide.

Foam looks like soap suds. Usually white and opaque, it hangs on the side of the mouth. Because it's thicker than drool, foam tends to hold its shape until your dog accidentally wipes or licks it away. Typically, it comes with severe panting.

10 Common Reasons Why Your Dog is Foaming at the Mouth

Mouth foam can be the result of many different issues. Some are health-related while others revolve around environmental factors.

Either way, it's essential to address the cause as soon as possible. While not all reasons are severe or dangerous, it never hurts to err on the side of caution.

To help you understand the foaming phenomenon a bit better, here are some common causes.

#1. Excessive Heat Exposure

Is the temperature outside scorching? If so, your dog could be on the brink of heatstroke. During the summer months, heatstroke is a potentially life-threatening issue that affects dogs of all sizes.

Even if it feels acceptable to you, the temperature could be way too high for your dog to spend much time outside. This is especially true if your furry friend has no access to cool water or shade.

Heatstroke occurs when your dog's body temperature reaches 104 degrees Fahrenheit. In a desperate attempt to cool off, they will begin to pant like crazy. The extreme air movement results in the formation of foam.

What you can do:

Get your dog into a cool space as soon as possible if you notice signs of heatstroke. In addition to foaming at the mouth, you may see your dog losing consciousness or becoming lethargic.

Provide cool water and do everything you can to lower their body temperature. Once things stabilize, bring your pup to a vet to ensure that no long-term damage occurred

To prevent excessive heat exposure you can use a dog cooling vest or jacket

#2. Too Much Physical Output

Overexertion is another common cause of foaming at the mouth. It's a similar effect to excessive heat.

Your dog's body is going through more than what they're used to. If they can't keep up, the heart rate will rise to dangerous levels. The same goes for body temperature.

Panting and drooling will ensue, which results in the rich froth developing.

What you can do:

The best way to address overexertion is to give your dog a break. Bring them inside to cool off and let them relax a bit.

#3. Stress or Anxiety

Believe it or not, stress and anxiety can cause foaming. Moments of distress lead to hypersalivation.

You might see this happen whenever you take your dog to the vet or any other place they hate. They begin to breathe harder. Pair that with the extra saliva, and foam starts to churn.

#4. Nausea

Have you ever noticed that your mouth gets watery whenever you're on the verge of vomiting? Dogs have the same reaction to the feeling of nausea.

It's the body's way of preparing them for regurgitation. Think of it as a defense mechanism. Extra saliva means more lubrication to let the vomit come out more smoothly.

Even if your dog never gets to the point of throwing up, hypersalivation and foaming are bound to happen. The foam can get even thicker if your dog starts to wretch.

What you can do:

Nausea can come from anything. It can occur due to medication, foods that don't agree with them, general gastrointestinal upsets, or motion sickness.

The best thing you can do is provide support and plenty of water. Bring your dog outside just in case and stay by their side until nausea passes.

#5. Bad Tastes in the Mouth

Dogs have a pretty nasty habit of tasting anything they can get their tongues on. It's the way they experience the world for better or worse.

Whenever they get a taste of something undesirable, drooling and foaming will usually follow.

That's because they don't have the ability to flush their mouths out as we do. Dogs don't even have the muscles to spit! So, they have to rely on saliva to do the work for them.

What you can do:

Drooling, panting, and foaming at the mouth is their only way to eliminate bad tastes.

There's not much you can do here except provide a bowl of clean water.

#6. Accidental Poisoning

Here's a potential cause for concern. Sometimes, foaming at the mouth is the result of accidental poisoning. As we mentioned earlier, dogs can get into all kinds of trouble with their tongues!

If they're unfortunate enough to lick or consume a toxic substance, they can experience many different types of reactions. Foaming is just one of them. Hopefully, it's the only adverse reaction they'll encounter.

It all depends on the toxic substance and how much of it they ate.

What you can do:

Either way, it's essential to contact your vet as soon as possible. Some toxic chemicals can lead to anaphylactic shock and death within hours. You must act fast to ensure that your dog doesn't is safe and healthy.

Interestingly enough, your dog is likely surrounded by toxic items. Many canines accidentally ingest pyrethrin when grooming themselves. It's a topical flea medication that's used in drops and collars.

Some plants and foods can cause poisoning, too. Everything from onions to sugar-free gum will cause unwanted reactions, so you must be careful about what your dog gets into.

$7. Distemper

Distemper is a viral disease that can have far-reaching effects on a dog's health. It's highly contagious and can be lethal without proper care.

Fortunately, distemper is pretty rare these days. The disease is covered by vaccines, much like rabies. However, dogs living in areas with lots of strays can still encounter it.

The disease attacks the nervous system. Dogs can suffer from breathing difficulties, gastrointestinal problems, and more.

Not all dogs with distemper will start foaming at the mouth. But, it is a common symptom.

What you can do:

The only way to avoid distemper is to get your dog vaccinated. There's no cure to the disease, and dogs rarely recover completely once it starts ravaging the body.

#8. Rabies

Rabies is the first thing most people in the general public think of when they see a dog that's foaming at the mouth. Like distemper, rabies is a viral disease that quickly spreads.

In dogs, rabies causes extreme aggression and erratic behavior. It's fatal and can even kill humans if the disease spreads through a bite or scratch.

The good news is that rabies is practically eradicated in domesticated dogs. It still occurs in wild animals, so unvaccinated dogs can still get the disease through contact.

What you can do:

If you suspect that a dog has rabies, avoid it at all costs and contact animal control for assistance.

#9. Seizures

Seizures can occur due to a wide range of underlying health issues. Some dogs suffer from chronic attacks due to brain conditions.

Others experience them because of renal failure or liver issues. Whatever the case may be, don't ignore the seizures.

The neurological event can cause lasting brain damage. Seizures cause your dog to lose control of its body. In addition to panting and hypersalivation, frothing at the mouth is common.

What you can do:

Seek veterinary care as soon as possible if your dog ever suffers from a seizure.

#10. Dental Issues

Is there a pungent smell emanating from the foam around your dog's mouth? If so, you might be looking at some serious dental issues.

Periodontal disease plagues dogs of all sizes, breeds, and ages. Bacteria slowly eats away at the tooth. In severe cases, the bacteria can cause tooth loss, cavities, abscesses, and more.

Dental diseases can also cause immense pain. This triggers salivation and panting, which results in the signature mouth foam.

What you can do:

Get your dog to the vet as soon as possible if you suspect that dental disease is to blame. Your vet can perform cleanings, extractions, and other procedures to alleviate pain and promote healing.


When you see foam churning around the corners of your dog's mouth, pay close attention to their behavior.

Look out for additional symptoms to pinpoint the root cause. From there, you can determine the right course of action.

Not every instance of a foaming mouth requires immediate intervention. However, it's always good to try and put a stop to it. Mouth foam isn't normal. Whether the root cause is benign or indicative of an underlying health issue, provide your dog with the care they need.

Also Read: 7 Common Causes of Smelly Ears in Dogs


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About the author 


Steve is a writer with over 10 years of experience in dog training and nutritiion.

His goal is to educate dog owners about the ins and outs of canine behavior as well as keeping up with the latest scientific research in the field.