Why is my dog foaming at the mouth?

When your dog suddenly starts foaming at the mouth, it’s natural to feel a surge of panic. The media has conditioned us to associate this symptom with dire scenarios, but the reality is often less dramatic. While some causes of mouth foaming can be serious, many are benign or easily treatable. The key is knowing how to differentiate between normal slobber and potentially problematic drooling. In this guide, we’ll demystify the reasons behind your dog’s frothy mouth, help you recognize when it’s time to worry, and provide practical steps for addressing this common canine issue.

What does foaming at the mouth look like?

Because of stories like Old Yeller, our first thought when we see our dog foaming at the mouth is rabies. However, there are plenty of other reasons why your dog’s mouth might be foaming. In fact, “foaming at the mouth” is simply a term for thicker, whiter drool. Some dogs tend to slobber more than others or are prone to heavier drooling.

Causes of dogs foaming at the mouth

The causes of this exceptionally viscous drool range from being a healthy dog to life threatening situations. Ultimately, only a vet can rule out particularly dangerous causes. Here are some of the reasons your pup might be foaming at the mouth:

Non-emergency reasons

Once your veterinarian has ruled out the life-threatening causes we’ll go over below, you’ll be able to consider these possible underlying causes for why your dog’s saliva is thick and frothy.

• Stress and anxiety. Just like us, dogs experience stress and anxiety in different ways. For some pups, they may pant, lick their lips, and even foam at the mouth.
• Dental disease. Tartar under the gum line leads to gingivitis which if left untreated will lead to periodontal disease. When periodontal disease becomes severe, gum recession, bone loss, tooth mobility, oral pain, and sometimes excessive, thick drool will result
• Nausea. While feeling queasy is more of an accompanying symptom than the root cause, dogs will sometimes foam at the mouth when they are experiencing an upset stomach as well.
• Too much activity. For some dogs, excessive slobber and foaming is just a sign that they’ve been having too much fun learning new tricks and have overexerted themselves.
• Their breed. Some dogs, like St. Bernards, Bloodhounds,  Boxers, Mastiffs, and other dogs with an impressive set of jowls produce more saliva, and it tends to be thicker and discolored.
• Medication. Liquid medications that taste unpleasant, or a pill getting stuck in your dog’s throat, can cause foaming. Some medications can also cause gagging, coughing, and repeated swallowing.
• Ingesting insects or certain animals. When dogs eat or lick stink bugs, lizards, frogs or toads, sometimes foaming at the mouth can occur due to the taste.  Some lizards, frogs, and toads can also be toxic and cause more severe symptoms as well.

Emergency reasons

While the reasons listed above can be concerning, they aren’t necessarily life-threatening. However, in some cases, excessive drooling or foaming can be a sign of a much more serious situation that requires immediate care.

• Poisons and toxins. Pets, particularly curious dogs, can easily ingest harmful chemicals. Antifreeze is a common and highly recognized example of this, but there are numerous other harmful products, such as plants, pesticides, and even some human foods that can be highly toxic to dogs if ingested.
• Seizures. A symptom of an underlying issue, seizures can sometimes be accompanied by excessive saliva or foaming, as well as loss of consciousness, muscle twitching, urination, and defecation. Knowing what to do in the event of a seizure, and seeking medical help, is important.
• Heatstroke. Unlike humans, dogs can’t sweat to help reduce their body heat. Panting is the most effective way for dogs to reduce heat and when they can’t, a heatstroke can occur.
• Rabies. Often the first virus that comes to mind when we see foam around a dog’s muzzle, rabies (Trusted Source) can be found in most of the world—the only real exceptions being some island nations.
• Bloat

What to do if your dog is foaming at the mouth

If it’s normal for your dog’s breed to produce an excessive amount of saliva and it hasn’t increased in amount, color, or viscosity, this may just be normal. If a change in behavior leads to excessive drooling and a significant difference in your dog’s saliva, though, it’s a good idea to bring your dog to the vet as soon as possible.

In some cases, the cause of your dog’s frothy drool may be something simple. To help your dog feel better with an upset stomach, we recommend mixing a little pumpkin into their food. Or, for those hot summer days, have water available to drink at all times and get your pup inside as soon as possible to help them cool down and stay comfortable.

If your dog is still producing foam or drool over a few hours then it’s time to head to the vet.

Frequently asked questions

What can cause a dog to foam at the mouth?

Heavy panting, medications, upset stomach, ingesting toxins and some illnesses can all cause dogs to foam at the mouth., if they don’t clear up quick and accompany other symptoms, it’s important to get to your vet as soon as possible.

My dog licked a frog, will he be okay?

Being naturally curious, it isn’t unusual for dogs to lick a toad or frog (or try to eat it) and the result may lead to foaming at the mouth. Fortunately, in the U.S., most frogs lead to only mild irritation. Two especially toxic types of toads—the Colorado River Toad and Cane Toad (Trusted Source) —that pose a serious risk to dogs, and both are found in the warmest parts of the country, namely Hawaii, Texas, Florida, Arizona, New Mexico, and California.

What signs indicate a dog has eaten poison?

Changes in behavior, seizures, tremors, vomiting, diarrhea, and foaming at the mouth can be signs that a dog has ingested poison. However, other symptoms are possible as well. Dog owners should call the Pet Poison Helpline (1-800-213-6680) immediately if a dog has ingested anything unusual. For a fee, the helpline service will be able to determine if the ingested item is toxic and if treatment is needed.