Why Is My Dog Foaming at the Mouth?

Have you ever noticed foaming along your dog’s lips? You probably wondered and worried about rabies. The good news is that if your dog has the rabies vaccine, then it is most likely not rabies.

There are many reasons why your dog might be foaming at the mouth. Find out the reason by reading our Milwaukee, WI, urgent care animal hospital‘s article below.

Dog Foaming At Mouth Milwaukee Wi


There are both benign causes and medical health problems that can cause foaming. We will go into the following list in more detail in a moment.

  • Aerated drool
  • Heat stress
  • Overexertion
  • Stress and anxiety
  • Motion sickness
  • Dental disease
  • Physical objects
  • Foul taste
  • Nausea and vomiting
  • Toxins
  • Gastrointestinal issues
  • Rabies

Aerated Drooling

If you are noticing occasional drool that is foaming, it could be a simple case of it being aerated. This means that a lot of oxygen is getting into the saliva. This type of foaming does not indicate any health problems.

However, if you are noticing a lot of foaming or it is happening a lot it may be a sign of a mild problem. These include:

  • Heat stress
  • Overexertion
  • Motion sickness
  • Stress
  • Anxiety

Heat Stress

If it is summertime or if it is hot and your dog starts foaming, then heat stress may be the cause. If it’s heat stress, you need to get your dog into an air-conditioned space immediately.

Heat stress and heat exhaustion are the first stages of heatstroke. It is important to cool your dog down before heatstroke ensues. Call your vet if you are worried about your dog.


Overexertion can lead to foaming drool. Dogs who are not used to high level physical exertion may start panting and the air from panting can aerate their drool causing foaming.

If your dog has been exercising, playing, running, etc., then you may need to give them a break.

Stress, Anxiety and Excitation

Stress, anxiety and excitation can also lead to foaming. When your dog is stressed or anxious, then the combination of panting, whining, and barking can aerate their drool causing foam.

Treating your dog’s anxiety and stress is the only way to stop and prevent further foaming. To treat stress and anxiety, you need to find out what is causing it. Common causes include:

  • New people
  • New animals
  • Strangers they can see from the window
  • Fireworks
  • Loud sounds
  • And more…

You can reach out your vet and talk to them about it. They may have some ideas and can help talk you through the steps of either removing the cause of treating your dog with desensitization training. This training desensitizes your dog to the stressor.

Motion Sickness

Motion sickness can cause anxiety, stress and nausea. Therefore, it can cause foaming at the mouth. If your dog suffers from motion sickness it may be necessary to talk to your vet about getting pills to treat it.

Dental Disease

Dogs suffering from dental disease and oral problems may foam at the mouth. Dental disease leads to excessive drooling and when aerated, this leads to foaming at the mouth.

You will need to contact your vet for treatment options. Depending on the dental problem, they will recommend a course of action.

Physical Objects

If your dog has swallowed something and it is lodged in their throat, it can lead to foaming at the mouth. Physical objects can also be something they are chewing on, such as a toy or stick. The chewing can lead to excessive drooling. If the object gets stuck in their mouth it will certainly lead to drooling and foaming.

Foul Taste

A foul taste in the mouth can lead to excessive drooling and foaming. This foul taste can be caused by dental problems or from licking/eating something with a foul or bitter taste

Nausea and Vomiting

Nausea and vomiting can cause foaming at the mouth. If the foaming at the mouth is followed by vomiting, it may mean your dog has eaten something that has caused an upset stomach. This could potentially lead to other health concerns and you should contact a vet or urgent care vet immediately.


If your dog has ingested toxins the first sign may be foaming at the mouth followed by vomiting. If you suspect they have ingested a toxin, contact your vet or the closest urgent care vet immediately. Toxins include:

  • Chocolate
  • Mint
  • Coffee
  • Caffeinated foods and beverages
  • Macadamia nuts
  • Avocado
  • Onion, garlic, shallot, scallions
  • Alcohol
  • Citrus
  • Grapes and raisins
  • Other nuts
  • Xylitol
  • Medications
  • Certain plants

Gastrointestinal Issues

Any issues in the gastrointestinal tract can lead to excessive drooling and foaming. This can be caused by a health problem, toxin, or physical object.


Since rabies (although unlikely if your pet is vaccinated), can be the cause of foaming at the mouth, it is best to have your pet checked out by your vet if you notice an unusual amount of foam in their drool. Especially if you notice other rabies symptoms.

If your dog has been bitten by another animal, it is important to know that they may have been exposed to rabies.

Other symptoms of rabies include:

  • Change in behavior
  • Anger
  • Distrust
  • Seizures
  • Paralysis
  • Unable to drink
  • Unable to eat
  • Coma

If Your Dog is Foaming at the Mouth due to an Emergency, Please Reach Out to Our Urgent Care Animal Hospital Immediately

While there are many normal reasons for a dog to foam at the mouth, you want to keep an eye out for an unexplained change in the foaming, such as an increase in foaming or in how often foam appears.

If your dog is foaming at the mouth due to a medical emergency, please reach out to our Milwaukee, WI, urgent care vets immediately at (262) 226-2055.