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Why Do Dogs Foam at the Mouth

↯ Key takeaway points

  • Dogs can foam at the mouth due to reasons such as exercise, stress, dental problems, difficulties swallowing, sickness, seizures, poisoning, and rabies.
  • Seizures and rabies are serious conditions that require immediate veterinary attention.
  • Some symptoms to watch out for include shaking, poor breathing, uncontrolled behaviors, and difficulty opening eyes.
A pet lover passionate about educating readers about animal health and care. Love reading studies and recent research.
Practicing small pets and equine veterinarian and junior teaching assistant in Veterinary Medicine.
Published on
Wednesday 29 January 2020
Last updated on
Wednesday 7 June 2023
Why Do Dogs Foam at the Mouth
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Seeing our pet dogs foaming at the mouth can be hugely distressing and upsetting. Immediately our minds will resort to the worst-case scenario and worry our pets are incurable. This is not always the case. It is worth reading on so we can explain each possibility and their symptoms and treatability.

Why dogs foam at the mouth?

There are a few reasons why your dog may foam at the mouth. Most of them are not cause for concern. Exercise, stress, and other oral problems can cause foaming at the mouth. Consumption of something that may have upset their stomach can also lead to foaming at the mouth, shaking of the head, and possible diarrhea. Other sicknesses may be more serious such as poisoning, seizures, and rabies. Foaming in the mouth of the dogs can also occur due to very hot conditions (hot room temperature or during the summer).


When your dog is running or playing a lot, they will begin to salivate more. A lot of exercise will also cause your dog to breathe heavily. The combination of heavy breathing and excess saliva can produce bubbly, white spit. This gives the impression of your dog foaming at the mouth. This will be visible whilst the dog is playing and afterward for up to half an hour. This is because some breeds produce more saliva than others for longer periods of time. If you only find your dog foaming at the mouth during or after periods of exercise or play, this is the most likely conclusion.

Allowing your dog to drink water and wiping away the excess drool can prevent the appearance of foam on your dog’s mouth. Drinking water can often prevent the saliva from accumulating near the front of the mouth. Also, make sure your dog is having regular breaks to ensure they are not over-exerting themselves. Although, a dog can usually tell their own limits. So do not assume foaming at the mouth means they are exercising too much.


This is similar to exercise if a dog is highly stressed they will begin to produce excess drool and hyperventilate. This can lead to the appearance of foam at the mouth. Dogs will produce more drool when they are stressed because of uncomfortable positions, habit, and upset stomachs.

Your dog may place themselves in odd positions or have a reluctance to move with increased stress. This may mean that they are not able to hold in the regular build-up of saliva. As increased anxiety also leads to increased panting, an open mouth will lead to excess drooling. Anxiety can also lead to repetitive habits. Your dog may pant repeatedly and allow drool to accumulate due to a reluctance to move. This is similar to stress licking where a habit is formed as a distraction or comfort.

Upset stomachs are caused by anxiety as they increase the production of Corticotropin-releasing factors which can cause the stomach muscles to tense and churn. This leads to your dog feeling sick, excess drooling and panting.

Difficulties Swallowing

This issue can be more serious. Something your dog swallowed may be lodged in their throat. Not disrupting their breathing completely but enough so that they are or close to hyperventilating. The excess drooling comes from an inability to swallow correctly and the body trying to aid in moving the foreign object. There is also the possibility of a growth of some sort in the throat, although this is less likely due to the location of growth.

If you are able to open your dog’s mouth and look to the back of their throat, do so to see if you can identify an object there. If so, you may need to reach into your dog’s mouth and pull the object out. Be careful not to hurt your dog or push it further back, and if you have any concerns, take your dog straight to the vet. They may be able to remove the object more quickly and smoothly, decreasing stress and pain for your pup.

If you can see a growth or mass at the back of your dog’s throat, take them to the vets. This may be non-malignant or cancerous. If a growth is present, your vet may take samples through swabs, scans or other tests. These are precautions and may not mean that the lump is anything to worry about. Sometimes growths may be removed by tablets or surgery.

Dental Problems

If your dog has periodontal problems, such as gingivitis or cavities, this can lead to your dog foaming at the mouth. This is because pain and numbness can cause your dog to keep their mouth open for long or aim their breath in a different direction to avoid it hitting an exposed tooth. Similarly, their tongue may always be out and hang a certain side to avoid a sensitive area.

Gingivitis is inflammation of the gums, usually due to plaque caused by a poor diet. Inflammation leads to swelling and pain to touch all around the gums. This is can eventually lead to tooth decay, loss of weight and excess drooling. The drooling along with the directed and odd panting is what can cause foaming at the mouth. Take your dog to the vet to treat the gingivitis. Brush their teeth and alter their diet to prevent it from returning. Cavities are holes present in the tooth which may expose nerves, this can be an incredibly sharp pain for your dog if air or food touches the inside of the hole. The pain leads to avoidance with the tongue and breathing, again a cause of foaming at the mouth.

dog mouth foaming
Dogs foam at their mouth regularly. It’s generally nothing to worry about!


Sickness in your dog can lead to frothing at the mouth, especially illnesses that cause your dog to have an upset stomach.

An upset stomach and bloat can lead to excess saliva and heavy breathing through two methods. Saliva is the beginning of the digestive system as it breaks down carbohydrates using an enzyme called amylase. Therefore this is used to attempt to digest anything remaining in the mouth and prevent nausea. Furthermore, due to hormonal release, nausea attempts to ‘speed up’ the digestive process and this includes the amount of saliva being produced.

Two serious forms of sickness that can cause your dog to foam at the mouth are seizures or rabies.


Seizures cause uncontrolled contractions of your dog’s muscles. This can mean they hyperventilate, relax their oral muscles and drool. When they hyperventilate, this can cause the spit to have bubbles and become frothy. Film your pet’s seizure and take them immediately to the vet afterward, showing them the film can help them identify how best to treat your dog.


Rabies is the most well known and feared cause of dogs foaming at the mouth. The virus affects our pets’ nervous system and means that they are unable to swallow. Hence why the foaming is constant. Immediately take your dog to the vets if you are worried they have rabies.


Foaming at the mouth usually occurs in a dog almost immediately after ingesting poison. This is because the body is attempting to rid the poison through extra digestion and lubricating the throat for potential vomiting. The frothing at the mouth will occur moments after the poisoning and can continue until treatment or until the moment of death if no treatment is provided. If you find your dog foaming at the mouth, attempting to vomit and no previous explanations fit your dog, go to the emergency vet.

What to do when your dog is foaming at the mouth?

As there are so many different reasons for foaming at the mouth, many of which require specific treatments, it is important to recognize the most likely cause for this behavior to properly treat it. If your dog is displaying worrying symptoms such as shaking, poor breathing or cannot open their eyes, take them to the vets immediately.

Is your dog is acting normal but foaming at the mouth?

If you suspect your dog is foaming at the mouth due to exercising, provide them with water, encourage them to rest and wipe away excess saliva with a towel. Your dog may also be stressed. Other signs of this include the whites of the eyes showing, repeated licking, excess aggression or hiding. In the case of anxiety, try to calm your dog by moving them to a less stressful environment or removing the stressful stimulus. You can also provide them with water, food, make the area quieter or, if wanted, provide the dog with physical comfort.

Is your dog shaking, having a seizure, vomiting, or struggling to breathe?

breathing problems in brachycephalic dogs
Brachycephalic breeds tend to have more breathing issues. They also tend to drool and foam quite a bit.

In this case, take your dog straight to the emergency vet. They will question the symptoms of your dog and immediately begin treatment.

An ECG and EEG may be used to check your dog’s heart rhythm and brain activity. This is because your dog’s brain activity will differ in a seizure depending on the cause. For example, epilepsy produces much higher spikes and more frequent spikes of brain activity during seizures.

In the case of blocked breathing, your vet will quickly check their airways for any blockages and remove them using a gloved hand. If the blockage is unable to be moved by hand or appears to be a growth, they may admit your dog immediately to emergency surgery. Although this depends on the severity.

If your dog is found to have rabies, they will immediately be placed into a ten-day quarantine. There is no accurate way of testing for rabies unless the animal is dead. If your dog displays physical signs and behavioral signs of rabies, such as increased aggression and a change in bark tone, the assumption will be made that they are infected. If their behavior and physical symptoms change within ten days, your dog will be re-examined and treated as such.

How to prevent dogs foaming at the mouth?

If a serious condition has affected your dog, it is going to be more difficult to prevent. But there are a few methods to prevent foaming at the mouth for your dog.


Both stressed dogs and overexerted dogs can benefit from being provided water as they can both lose large amounts of fluids. Use a water fountain as dogs love these!

Panting, drooling and sweating can occur in exercising dogs and those that are anxious, therefore topping up this fluid can help prevent foaming at the mouth. As these situations can occur at any time, you should make sure to have water available at all times. Bring a water bottle with you and a dog bowl whenever you take your dog out of the home. Also, make sure that there is always water available for your dog at home and it is fresh and clean.

You can also make sure your dog is well hydrated before a walk or stressful event to prevent dehydration. Encourage them to have a drink before exercising (e.g. before a walk or playing). Be sure to do the same before a stressful situation such as New Year’s Eve with fireworks or a car ride.

Dental Care

There are multiple methods you can take to help with your dog’s dental care. If the problem is more severe, such as a tooth infection or cavity, you should always take your dogs to the vets. They can perform tooth removals, prescribe antibiotics and give thorough tooth cleanings that you may not be able to.

A good at-home method of treatment is to regularly brush your dog’s teeth to prevent plaque and inflammation. Make sure to use dog-friendly toothpaste and to brush firmly but not enough to cause pain. You can also provide your dog with healthy, dental chews to aid with strong teeth and diminish plaque. There are also many toy brands you can use to promote healthy teeth, some even with the involvement of doggy toothpaste for extra dental benefits.

professional dental cleaning for dogs
Never hesitate to schedule an appointment for your dog to get a professional dental cleaning.

Removing Toxic Items

Items inside and outside your home can be toxic to your dogs! Common toxic items include frogs, plants and household cleaning products. Checking your yard regularly for plants that may be poisonous and properly uprooting them can prevent your dog from ingesting them. If you are in an area with venomous toads or frogs, always have a quick check around the yard before letting your dog out. A further precaution can be to put in fencing around your yard without gaps, so frogs and toads cannot enter.

When it comes to household products, your dog may access them by pushing open cupboards or jumping onto surfaces and chewing through bottles or containers. Make sure all cupboards with toxic products are sealed well, for mischievous dogs you can even add child locks onto the doors. Any products kept on surfaces should also be moved into a safe container to prevent your dog from getting to them.

Proper Diet

An unhealthy or improper diet can lead to poor dental hygiene, an upset stomach, and dehydration. Therefore this prevention method is essential. Make sure to provide your dog with the right nutrients, minerals, and percentage of food for their gender, breed type, and age to help them maintain high health. Furthermore, it can make them feel better internally and externally. Use fiber such as prebiotics too!

Food brands are usually specified, so make sure to buy a brand that is appropriate for your dog’s age and breed. Furthermore, make sure you are feeding them the right amount for their size and activity levels, overweight or underweight dogs have higher stress levels. Dogs require certain nutrients to survive and thrive. The six nutritional requirements for dogs are vitamins, minerals, carbohydrates, protein, water, and fats. As dogs are omnivorous, it is often recommended to provide them with a well-balanced diet. Some healthy food brands we recommend are Orijen and Stella and Chewy’s.

keto macros for dogs
Guidelines of keto macros for dogs – a recommended diet!

Therefore, if your dog is foaming at the mouth, this does not mean they automatically have rabies. Check their behavior, physical symptoms, and the surrounding environment to help identify the cause. Always remember to contact a vet if you have any concerns. Your dog’s health is never silly to worry about.

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