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Why does my dog’s mouth foam while eating?

Foaming at the mouth is often associated with rabies, but there are many causes for it. In fact, rabies is rare in dogs who are properly vaccinated. There are far more likely reasons for your dog becoming a foam factory, from normal bodily functions to serious health issues. 

Why does my dog’s mouth foam while eating?

If your dog is foaming at the mouth while eating, you’ll need to do some detective work to determine the cause. 

What Causes Drooling and Foaming?

Drooling is a normal bodily function for dogs. It’s a nervous system reaction. Normally, drool functions similarly to saliva in humans. It helps your dog digest their food and keeps their mouth healthy. 

Put simply, foaming occurs when drooling meets panting. The liquid combines with oxygen, causing foam. Think of dish detergent. When mixed with water, it begins to foam and bubble. Air and drool have a similar reaction. 


Some breeds are more likely to drool and foam than others. Bloodhounds, Saint Bernards, and Mastiffs have mouths that allow drool to build up in their mouths more than other breeds. The extra skin collects the drool which will pool and eventually flow out of their mouths. Of course, excess drool can also mean excess foam. 

When the Foaming Started

The first step to figuring out why your dog’s mouth is foaming is to think about when it started. Is it something that typically occurs? Did it begin with their most recent meal? Did they eat something they shouldn’t have?

If it’s typical for your dog, it may simply be normal. It could also be related to stress or stomach upset.

If it just began suddenly, it may have been something they ate. If it came on suddenly, it’s very important to figure out the cause, because they could have eaten something toxic. 


Considering your dog’s behavior can help you determine the cause of the foaming. If they seem fine other than the foaming, it’s likely just a natural occurrence and nothing to be concerned about. 

If they are whining or restless, they may have stomach upset or ingested something toxic. If they are lethargic, you can assume that they aren’t feeling well, and that something may be wrong. 


Behavior can also give you clues as to whether you should be concerned about rabies, which is the most well known cause of foaming at the mouth. The good news is rabies is rarely the cause. 

A dog with rabies will behave very differently than normal. Rabies always brings behavioral changes, but this doesn’t always mean aggression. Your dog may become more affectionate, shy, or aggressive. If your dog is typically high energy, they may be lethargic and disinterested. A relaxed dog may become high energy or easily excitable.

They become sensitive to light and develop a fear of water. They often have pica, which means they eat nonfood items. In addition to foaming at the mouth, fever, loss of coordination that causes staggering, and eventual paralysis occur.  

Food Taste 

Have you ever said something sounds so tasty it makes your mouth water? Dogs will drool when they are anticipating food, which can also lead to foaming. 

They may also drool and foam while eating, because saliva is triggered to help break down food. 

At the same time, unpleasant food can cause your dog to foam while eating. Food that tastes bad or bitter can also cause your dog to foam at the mouth. 

If your dog was eating their food, check it for rancidity. Dog food can go bad after 1 month after opening. Oxygen exposure can cause the fats in the food to oxidize. Over time, it loses flavor and nutrition. It can begin to taste bad. 


Nasea causes excess drool and panting, which can obviously cause foaming. If your pooch is foaming at the mouth due to nausea, they may also have other symptoms. 

These can include diarrhea, vomiting, or gagging. If your dog is experiencing these symptoms, consider what they were eating when or before it occurred. 

It’s possible that they are allergic to an ingredient in their food. They may also have gastrointestinal issues, like acid reflux. 


Bloat is a life-threatening condition that occurs after your dog eats. It occurs when gas gets trapped in the stomach. As food breaks down, more gas builds up. This causes the stomach to become painful and swollen. 

Just like nausea, bloat will cause your dog to drool excessively and pant, which can cause their mouth to foam. 

Your dog will not be able to pass gas, poop, or vomit. They will retch, attempting to vomit, but nothing will come up. They will clearly be in pain, and may also be restless. 

Bloat requires immediate veterinary attention. If it’s not treated quickly, the pressure can cause the stomach to twist. This requires surgery to treat, and is often fatal if not treated in time. 

Bloat comes on quickly. Your dog can go from fine to being in serious danger within a few hours. If you see the signs of bloat, seek immediate veterinary treatment. 


When it comes to  substances that are poisonous or toxic, there are a surprising amount  of dangers lurking in your home. Most cases of dog poisoning occur because the dog accidentally ingests something toxic. 

It’s no surprise that some human medications can be poisonous to dogs. After all, they can also be poisonous to humans, in incorrect dosages. 

However, you may not be aware that certain people foods are also dangerous for your dog. Chocolate, garlic, onions, and grapes can all make your dog very sick. 

Other dangers around your home include cleaning products. Dogs explore the world with their mouth, and they certainly don’t read product labels.  

Plants can also make your dog sick. Dogs will occasionally eat grass or other plants. Some houseplants are toxic to your dog. If they eat them, it can cause them to be sick and foam at the mouth. 


Stress can also cause your dog to foam at the mouth. Stress causes excess drool and panting, the key ingredients that create foam. If it occurs when eating, ask yourself if eating is stressful for your dog. 

If you have multiple dogs, this may be the cause of stress. In the wild, the alpha will eat first. This can cause issues if you feed multiple dogs at the same time in the same area. 

If the area is noisy or chaotic, this can also cause your dog stress. High traffic areas are not ideal places for mealtime, for you or your dog. 

Your dog may have dental issues. Just like people, dogs can experience tooth or mouth pain, particularly when eating. This will naturally cause stress and foaming at the mouth. 

Lastly, if your dog has had a negative experience while eating, they may experience stress. Even if the situation has passed, your dog will have a memory that something bad happened while eating, which will cause them to be nervous. 

What to do if my dog’s mouth foams while eating?

If your dog is foaming at the mouth while eating, what you should do will depend on the cause. In some cases, you don’t need to take any action. In others, you may need to seek immediate veterinary care. 

Food Taste

If you suspect food taste is causing your dog to foam at the mouth, check your pooch’s food. Does it smell off or rancid? Is it old? Has it been exposed to moisture? Have you changed their food recently? 

If your dog is foaming because they love their food, there’s no need to change anything. If you suspect the food is bad, change their food. You may also want to have your vet perform allergy testing, particularly if changing their food doesn’t solve the problem.


If stress is causing your dog to foam, you’ll need to eliminate the source of stress if possible. Feed your dog away from other dogs and in a quiet area. 

Try changing the feeding location and food bowl if your dog has had a bad experience. Check your dog’s teeth for signs of decay or injury.  

Seeking Veterinary Care

If you think poisoning, bloat, or rabies is causing your dog to foam, you’ll need to get them to the vet immediately. These conditions are life threatening, and time is of the essence. 

If nausea seems to be the culprit, monitor your dog. If it continues or is severe, bring them to the vet. If they have frequent bouts of nausea, this also needs to be evaluated by your vet. 

Why is my dog foaming at the mouth and not eating?

There are a few reasons why your dog may foam at the mouth and not eat. It’s natural to be concerned, but it’s not always serious. 


Just like humans, dogs can have seizures. Signs of seizures include foaming at the mouth, convulsions or shaking limbs, disorientation, and loss of consciousness. 


Too much exercise can cause your dog to foam at the mouth. It may also cause them to lose their appetite temporarily. Their body needs time to recover before they are prepared to eat. 

Naseau and Bloat

Nasea or bloat can also cause your dog to foam at the mouth and not eat. If your dog is nauseous, they may refuse food. Bloat causes stomach pain, so your dog will avoid food. 

What to do if my dog foams at the mouth and does not eat?

Again, it will depend on the cause of the foaming. Your dog may simply require a rest, or they may need medical care. 


If your dog has a seizure, bring them to the vet immediately. Seizures can be caused by epilepsy or an underlying medical condition. There are medications that can help you manage epileptic seizures in your dog. 


If overexertion seems to be the cause, your pooch simply needs rest. Give them plenty of water and a comfortable place to recuperate. In the future, monitor their activity level, and avoid allowing them to overexert themselves. 

Heavy panting and fatigue are signs it’s time for your dog to take a rest. If they are too hot, bring them into the shade and give them water. 

Naseua and Bloat

Mild nausea can be monitored at home. If it’s severe, then you should make an appointment with your vet. Ask your vet if it’s ok to give some over-the-counter medications, like Pepto bismal, and in what dosages.

If your dog is experiencing bloat, they will need immediate treatment.