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Why does my dog drool when sleeping?

Why does my dog drool when sleeping?

Drool is a fact of life. Dogs, like humans, drool. It’s a natural bodily function. However, excessive drooling can indicate a problem. If your dog is drooling while sleeping, it’s important to determine the cause. Is it normal, or is there an underlying medical issue? 

Why does my dog drool when sleeping?

There are lots of reasons why your dog may drool when they sleep. Drooling is normal to some extent, and some breeds are more prone to drooling than others. However, it can indicate a medical problem that needs to be treated. 

Why Dogs Drool When Sleeping

Drool serves a purpose for dogs and humans. It is actually saliva. When you put food into your mouth, the digestion process begins before you swallow. Saliva begins to break down the food, and prepares it for swallowing.  

Dogs saliva lacks the enzymes that help humans break down food before it hits the stomach, but it does serve similar purposes. It lubricates the esophagus and moistens the food, making it easier for it to travel through the esophagus.

Dog saliva also has antibacterial properties, which is why dogs lick their wounds. This helps keep their mouth healthy. 

When sleeping, this saliva pools in the mouth. The muscles are relaxed during sleep, which can allow the saliva to escape the mouth, resulting in drool. 


Certain dog breeds are more prone to drool than others. These include Mastiff, Bloodhound, Basset hound,Great Dane, Newfoundlands, Bulldogs, and Saint Bernard. Their head and mouth are shaped differently, so their lips aren’t able to contain their drool as well as other breeds. 

They also have extra folds of skin around their mouth and muzzle. This gives their face that adorable wrinkly appearance. It also provides spaces for saliva to accumulate, eventually overfilling and coming out as drool. 

When they sleep, the drool increases. Saliva pools in the folds of their mouth, and then drips out once the folds are full. 


Just like humans, dogs dream. Exactly what they dream about isn’t known, but researchers suspect they are reliving moments from their day. However, they seem to be capable of having both good dreams and nightmares. Perhaps they are chasing a rabbit, or perhaps the rabbit is chasing them. 

If a dog is dreaming about food, they may salivate. Salivation is a physical response to food stimuli. Have you ever noticed that when you mention your dog’s favorite treat, they begin to drool? Perhaps you’ve seen them enviously eyeing your dinner and drooling as well. 

If a dog is thinking, or dreaming about, food, the increased salivation can cause them to drool. This is a reasonable explanation if your dog only drools when sleeping occasionally. If it’s a nightly occurrence, you should look to other causes. 

Mouth Problems 

Mouth problems can cause excessive drooling when sleeping. If this is the cause, they may drool excessively when awake as well. Gum inflammation is one cause of drooling. The inflammation can be caused by gum disease or infection. Tumors in the mouth or esophagus can also trigger pronounced drooling. 

Have you ever had a toothache or mouth infection? Did you notice that you had more saliva? Humans work very hard to avoid drooling when awake, swallowing excess spit before it can make its way out of our mouth.

When we sleep, drooling is more common, particularly if we have a mouth issue. Your dog can have the same experience. Essentially, anything that negatively affects your pooch’s mouth or ability to swallow can cause drooling. 


Teething can cause your pup to drool. If you have a pup that wants to chew everything in sight, chances are this is why they drool. The pain and inflammation from teething can cause excess saliva production. You may be able to see your pups teeth coming in by looking into their mouth.

Stomach Problems

When you think about drooling, stomach issues probably aren’t the first thing that comes to mind. However, nausea and other stomach issues can cause drooling. One theory is that the drool helps protect the throat and mouth when a dog vomits. 

Vomit contains stomach acid. When nauseous, the stomach acid can be higher than normal. So when it is vomitted up, it can cause irritation or even burns in the mouth and esophagus. Saliva can provide a protective layer between the acid and the sensitive tissues. 

Liver or Kidney Disease 

Liver or kidney disease can cause excessive saliva production, also known as hypersalivation. This excess saliva comes out as drool. 

The liver and kidneys are filter organs. Their role is to help rid the body of toxins. When they malfunction, the body will use saliva to attempt to rid itself of toxins that aren’t being filtered out by the liver or kidneys. 

Liver or kidney disease will produce other symptoms as well. These include lethargy, weight loss, loss of appetite, an increase or decrease in thirst, confusion, and weakness. 

Why is my dog suddenly drooling while sleeping?

If your dog has always drooled when sleeping, it may be normal for them. However, if the issue begins suddenly, there’s nearly always a medical issue that is the cause. 

Foreign Objects

Dogs are famous, or infamous, for putting inappropriate objects in their mouths. These items can get stuck in the teeth or gums, causing excess salivation. In addition to their love for chewing things that are not food, food items can also get stuck. Bones are a common culprit, but pieces of meat, vegetables, and fruits are also possibilities. 

The easiest way to determine if this is the issue is to examine your dog’s mouth. If the object is visible, you can attempt to remove it. Be careful that you don’t dislodge the object and allow them to swallow it, however.

Cavity or Broken Tooth

A cavity or broken tooth can also cause your pooch to drool. When there’s a problem with a tooth, it’s common for your dog’s body to produce excess saliva, which causes drooling. 

Just like a foreign object, a look inside your dog’s mouth can tell you if this is the cause. Other signs include reluctance to eat or obvious pain while eating. 

Eating Non-Food Items

Non-food items can get stuck in your dog’s mouth. However, they can also cause stomach upset that leads to drooling. If your dog eats something toxic, they will drool excessively in an attempt to rid it from the body. 

The most common toxins for dogs include household cleaners and insect or rodent poisons, toxic houseplants, and toxic foods, particularly foods containing xylitol. 

In addition to excessive drooling, you may notice foaming of the mouth if your dog eats something toxic. Stomach upset, including diarrhea and vomiting, will likely occur as well. 

Respiratory or Sinus Issues

An infection of your dog’s respiratory system or sinuses can also lead to drooling. This can be caused by drainage or throat irritation. Signs of respiratory problems include a cough, wheezing, sinus drainage, and sneezing. 

Allergies can also cause drooling, for the same reasons as an infection. Other signs of allergy include sneezing, nasal congestion, nasal discharge, and itchy or swollen eyes. 


Rabies is the most feared cause of drooling. In addition to drooling, a dog with rabies may foam at the mouth. Rabies is a disease passed on to other animals through a bite. If your dog has not had a rabies vaccine and was recently bitten by another animal, it’s possible they have rabies. 

Other signs of rabies include fever, difficulty swallowing, personality changes, seizures, and paralysis. While aggressive, or furious, rabies is the most well known, and scary form, the other form is actually more common. Often called the “dumb” form of the disease, animals with this type of rabies lose their fear and become more docile. 


Just like humans, dogs can have seizures. This can be caused by epilepsy or another underlying condition. In addition to drooling, seizures often cause convulsions and confusion. Severe seizures can cause full body convulsions, while partial seizures may cause tremors in one part of the body. 


A dog with bloat isn’t likely to be sleeping, but drooling is a well-known sign of the life-threatening condition. Bloat causes a build up of gas in your dog’s stomach. The gas can’t make its way out. As food digests, gas and pressure increase. Your dog may be nauseous but unable to vomit. Their stomach will swell, and they will clearly be in pain as things progress. Bloat can be fatal within hours after the start of symptoms. When treated early, most dogs make a full recovery. 

Is it normal for dogs to drool while sleeping?

It is normal for dogs who are prone to drooling, including Mastiffs, Bulldogs, and Great Danes to drool when they are sleeping. Essentially, if your dog has a wrinkled face or generous jowls, drooling while sleeping is likely normal. 

If it’s something your dog has always done, it may be normal for them. If it starts suddenly, however, you should definitely work to determine the cause of the drooling. 

The volume matters as well. If your dog normally has a drip or two while sleeping, and suddenly begins soaking their favorite blanket with drool, there could be a problem. 

What to do about my dog drooling while sleeping?

If your dog is drooling when sleeping, there are a few things you should do, depending on the cause of the drooling. First, it’s important to know when drooling can indicate an emergency. 

When to Worry

Drooling can be perfectly normal, or indicate a problem that needs veterinary treatment. Occassionally, it can indicate a serious condition that requires emergency treatment.

If your dog experiences neurological symptoms, including seizures or difficulty standing, or cognitive issues like confusion or disorientation, get them to the vet immediately. Foul smelling saliva, saliva with blood, or very thick saliva should also be treated immediately.

Bloat also requires immediate treatment. Symptoms of bloat include a swollen or distended stomach and an inability to pee, poop, or pass gas. Your dog will likely gag, but will not be able to vomit anything up. Bloat can be fatal if not treated quickly. 

Check Their Mouth

Assuming your dog doesn’t have any of the severe symptoms listed above, the first thing you should do is check their mouth for any mouth problems or foreign bodies. If you notice any tooth or gum problems, you’ll need to make an appointment with your vet. If you find a foreign object that you can’t remove yourself, this will also require veterinary treatment. 

Checking With the Vet

You’ll need to consult your vet if you notice any changes in appetite or behavior along with drooling. If your dog is experiencing vomiting or diarrhea for no obvious reason, this also needs to be evaluated. Your vet is the best person to determine the cause of drooling and a course of action, if a medical issue is to blame. 

Stomach Upset 

Some cases of minor stomach upset can be treated at home. If you suspect acid reflux or indigestion is the culprit, you can give your dog Pepcid. They may take .25-.5 mg for each pound of body weight. 

Over the counter Pepcid strengths range from 10 to 40 mg per tablet, so be sure to include the correct strength when determining dosage. For example, a 20 pound dog could safely take 1 10 mg tablet, or 1/4 of a 40 mg tablet. 

You can also give your dog Pepto Bismol for nausea. The dosage is 1 teaspoon per every 10 pounds of body weight. For a 20 pound dog, the dosage would be 2 teaspoons. Most experts recommend no more than 6 teaspoons for large dogs. So, if your dog weighs 80 pounds, you will need to give them a maximum of 6 teaspoons of Pepto. 


If your dog is simply a natural drooler, there’s only one reasonable option. You’ll need something to soak up all the drool. You can accomplish this by laying a towel in their bed. You can also purchase doggie bandanas, which are designed to absorb excess drool. They are also adorable.