Why do dogs drool and is it normal to drool a lot? We look how to spot excessive dog drooling and what to do about a drooling dog.
As a dog owner you’ll know that all dogs drool from time-to-time. Some more than others.
Mostly dog drooling is normal but excessive drooling in dogs – more than usual – can be a warning sign of a health problem.
We’ll take a look where drool comes from and at the reasons behind normal drooling. Then we’ll discuss the possible reasons why suddenly your dog is drooling a lot – and what you should do about it.
Firstly, let’s answer the question “What is drool and why do dogs drool naturally?”
Dog drooling explained
All dogs are able to produce copious amounts of slightly sticky saliva
Producing lots of saliva when they are about to eat, helps a dog to break down their food and to swallow crushed bones safely.
Saliva also keeps the mouth moist and helps to prevent tooth decay and gum disease. It’s 98% water but also contains various enzymes, proteins, minerals and antibacterial compounds.
The saliva comes from glands that open through ducts into the dog’s mouth. The signal for the glands to start producing more saliva come from the dog’s brain in response to a number of different triggers.
We’ll look at those triggers in a moment.
Just like we do, dogs usually simply swallow any saliva they produce. So what causes drool to spill out from a dog’s mouth.
Why do dogs drool?
Dog drooling happens for several reasons.
- Either the dog’s mouth is trapping normally produced saliva, and releasing it all at once in a rush.
- Or the dog’s glands are making an abnormal amount of saliva (hypersialosis)
- Or, the dog is having trouble swallowing a normal amount of saliva (pseudoptyalism)
Excessive drooling from either of the last two reasons are seen to be abnormal and vets refer to this as ptyalism.
The first of the three reasons is not usually a cause for concern, we tend to think of it as ‘normal’ drooling, and it tends to be breed related.
Why does my dog drool all the time?
Wolves and other wild dogs don’t normally drool. Dog with faces that are still ‘wolf shaped’ don’t normally drool.
The main ‘normal’ drooling offenders in the dog world, are those who have been bred with loose, jowly faces – like Bloodhounds, Mastiffs and St Bernard’s.
Think of ‘Beethoven’, the St. Bernard, in the classic nineties film. The movie delights in showing a slow motion view of the drool flicking around his face.
The reason for slobbering in dogs with loose soft jowls is that the skin folds form pockets around their mouths.These pockets trap the saliva which then overflows when they’re filled to the brim.
Unfortunately, there isn’t a lot you can do about this. Other than keeping a towel handy. Constant drooling does keep your dog’s lips and the skin around their mouth wet all the time and this can cause irritation and inflammation.
Fortunately, Labradors do not in general have a big problem with this. Although some do have a looser facial skin structure than others.
But for the most part, if a Labrador starts drooling, it needs a little investigation.
There are both physical and psychological reasons why dogs drool and it’s important that we make sure our drooling dog doesn’t have a problem.
Let’s have a look at the triggers of ‘normal’ drooling in dogs.
Food triggers dog drooling
The most common reason, and one that many Labrador owners will be familiar with, is the anticipation of food!
We’ve already seen that dogs produce a lot of saliva while eating. This helps everything to slip down nicely and for digestion.
Anticipation of food is a psychological trigger for the production of saliva. For us as well – but dogs seem to be better at it.
This was probably the reason why Pavlov used dogs for his famous stimulus response experiments. He measured the amount of saliva produced by dogs after he trained them to associate a ticking metronome with food.
In the same way, your dog hears you getting his bowl out, he hears food being tipped into it. Then you expect him to sit and wait before tucking in!
All that anticipation sets those salivary glands into full swing. The results may be enough liquid to spill from the sides of your dog’s mouth.
In addition to the excess saliva, your dog may also be focusing so intently on you that he forgets to swallow as often as he normally would.
Many dogs, will also drool like this when watching people eat. This tends to happen when the dog has been fed from the table or during a human meal.
So if your dog drools while you’re enjoying your supper, the chances are that someone has been slipping them some titbits.
Another psychological trigger for dog drooling could be stress.
Dogs drool when anxious
Dogs that are anxious, nervous or even excited may pant and drool.
You can recognise anxious drooling by looking for other signs of stress as well, such as panting, pacing, whining, barking, and shaking off.
Riding in cars can trigger drooling in some dogs, partly from anxiety and partly through motion sickness.
Dog drooling from motion sickness
It can be hard to separate anxiety from actual motion sickness.
Some dogs don’t do well travelling in cars. They might be very happy to know that they’re going for a walk, but the motion of the vehicle disagrees with them.
Not all dogs who get travel sick will vomit or mess in the car. Some might just drool.
If you are worried that your Labrador is suffering from travel sickness, there are things you can do to help him.
Take a look at this helpful article on Travel Sickness in Labradors to find out more. Once your dog is feeling better, he’ll probably drool less as a result.
But what if your dog is drooling today and he wasn’t drooling yesterday. Chances are that something is wrong.
Because saliva is linked to the mouth this is the first place to look for the cause of your dog drooling a lot suddenly.
Mouth problems that cause dog drooling
Problems in their mouths that can cause excessive drooling in dogs are:
- Dental problems. Like build-up of plaque on his teeth and gums, a dental abscess or a broken tooth. Keep in mind that puppies could also drool when they lose their baby teeth.
- Infection. Usually seen as redness and swelling inside the dog’s mouth.
- A foreign object. Like a stick, bone chip or a piece from a plastic toy stuck between the dog’s teeth, in their gum, palate or even under their tongue.
- Injuries. Cuts, scrapes or bites.
- An abnormal growth the dog’s mouth.
- An abscess or other condition affecting the salivary glands.
A further sign that your pup might have a mouth problem is when the paw at their face. You may even notice that they are chewing only on one side of their mouth or refuse their dry kibble while still eating soft food. Or they might not eat at all.
So the first thing you should do when you notice that your dog is drooling more than usual is to have a good look inside their mouth. Also check if your dog’s saliva is normal. Is it maybe foul smelling, thicker, foaming, or is there blood in it.
Take your pup to the vet if they won’t let you check their mouth or if you find anything that’s unusual and worrying.
You might be able to remove a foreign object yourself. But look carefully whether there are any injuries and keep an eye over the next few days. A small injury could become infected or you might have missed a painful crack in a tooth – at the back or at the gumline.
Another common cause of dog drooling is when they’re too hot – panting and with their mouths open. Overheating could progress to heatstroke very quickly.
Dogs can and do suffer from heatstroke, and it’s a medical emergency. Short nosed breeds, like boxers, bulldogs and pugs are especially vulnerable to heat stroke. With their short faces they’re unable to pant and cool off effectively.
So when it’s very hot and your dog is drooling they may be overheating. Take steps to cool them down while you phone your vet for instructions.
Always make sure that your pet has shade and plenty of water in hot weather.
We’ve had a look the usual reasons why dogs might be drooling. However, there are many other, less obvious, causes of excessive drooling in dogs.
More causes of dog drooling
With these conditions your dog might start drooling a lot suddenly or, especially in the case of more serious illness, it might build up over time.
- Allergies and infections. Conditions that affect your pup’s nose, throat or sinuses can make it difficult for them to swallow, and then they drool.
- Rabies. This is a serious infection where one of the main signs is drooling, even foaming at the mouth.
- Poisoning. Dogs can be poisoned in different ways. Even by eating common plants like azaleas or chrysanthemums. They could also be poisoned by chemicals such as pesticides you use in your garden or household cleaners.
- Upset stomach. Anything that causes stomach pain, and/or diarrhea and vomiting is usually accompanied by drooling.
- Liver and kidney diseases.
- Disorders of the nervous system, especially those that affect the muscles.
Dogs will probably have other symptoms as well if they any of these conditions. Watch your pup for changes in behaviour, loss of appetite, fever, shakiness and any other signs of illness.
You’ll need to take your dog to the vet and provide as much information as possible for them to make a proper diagnosis.
Dog drooling diagnosis and treatment
You vet will examine your dog for the cause of excessive salivation – probably starting with the mouth. If he doesn’t find the cause there he’ll need to do further tests and examinations to get to the root of the problem.
He might even suggest blood or urine tests, biopsies, X-rays or scans.
Once the vet finds the cause of your dog drooling they’ll discuss treatment options with you and help you decide on the best course of action.
Why do dogs drool? – Summary
Dogs do drool normally for various reasons – some more than others. Most often if a treat or their dinner is involved.
However, never just ignore it if your dog drools a lot more than usual – whether it happens suddenly or over time. Your pet needs you to take action.
Maybe you’ll be able to identify a simple problem that you can deal with – like motion sickness, stress or an object stuck in his mouth.
For any other problems, or if you can’t find a cause for your dog drooling, take your pup to the vet. It could be a serious condition that needs proper diagnosis and treatment.
This article has been extensively revised and updated for 2019.
- Buzhardt, L. 2016. Dealing with drooling. VCA Hospitals.
- Gibeault, S. Is your dogs’s drool cool? When it’s natural and when it’s a cause for concern. American Kennel Club.
- McLeod, S. 2018. Pavlov’s Dogs. Simply Psychology.
- Reiter, AM. Salivary Disorders in Small Animals. MSD Veterinary Manual.
- Wag! Ptyalism in Dogs. Wagwalking.com
- WebMD. 2017. Why does my dog drool so much. webmd.com
The Labrador Site Founder
Pippa Mattinson is the best selling author of The Happy Puppy Handbook, the Labrador Handbook, Choosing The Perfect Puppy, and Total Recall.
She is also the founder of the Gundog Trust and the Dogsnet Online Training Program
Pippa's online training courses were launched in 2019 and you can find the latest course dates on the Dogsnet website