Saint Bernard dog drooling

Saint Bernard dogs are known for being droolers

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Why is my dog drooling?

By Karen Wild, CCAB Certificated Clinical Animal Behaviourist Animal Behaviourist

Updated on the

Whilst all dogs are cute, drooling is definitely not that easy to cope with! Let's find out why dogs drool, and how to manage excessive drooling in dogs.

A dog drooling isn't uncommon, on the contrary. There are many reasons why dogs drool, some more worrying than others. While for some breed it's normal to drool, for others excessive drooling could be a sign of dental problem, infection, liver of kidney problems.  

Why is my dog drooling?

A certain amount of drooling is perfectly normal. In fact, it’s healthy - saliva helps dogs digest their food. Drooling could be a side effect of panting, which is a perfectly natural way for dogs to cool down. But excessive drooling (otherwise known as hypersalivation) could be a sign of illness or stress, or a foreign body caught in the dog’s mouth or throat. It’s really important to know why your dog is drooling.

Do some dogs drool more than others?

Yes, and it's related to the shape of their mouths. Some dog breeds like the Mastiff and St. Bernard have thick, loose lips that struggle to control the flow of saliva and drool. The saliva then collects into the folds of their loose skin around the muzzle, and drops from the flews (pendulous upper lips) or is flung into the air when they shake! Other dogs with the same problem include Bloodhounds and Newfoundlands. There's nothing you can really do to stop it.

Usually, dog owners who go for such a breed know what to expect and are always stocked up on tissues or paper towels. A drool rag or a dog bib to tie around the dog’s neck is also a great idea if you want to protect your floor and your dog’s shiny coat. You also need to ensure that their skin and fur does not remain wet for any length of time, as this can lead to bacterial growth and infection.

Excessive drooling in dogs: What is drooling a sign of?

It's difficult to define excessive drooling. For example, some dogs drool a lot when they're hungry. Much like us, they’ll salivate at the sight or smell of their favourite treat! Others drool when they're excited or nervous. In cases like these, the drooling is directly related to a stimulus. Once that's removed, or satisfied, the drooling will usually stop.

So most of the time, drooling is not a cause for concern. However, you should pay more attention to it if drooling is unusual for your dog. For instance, if your dog was not much of a drooler before, and all of a sudden he begins to drool without stopping, there may be something amiss. So if you notice a big change in their drooling habits, or if they appear to be drooling for no obvious reason, then there's probably an underlying cause. Excessive drooling can be related to any of the following:

Foreign Objects

The first thing you should do is check your dog's mouth and see if anything is lodged in their teeth or throat. If your dog is drooling excessively, it could be that something is blocking their mouth or throat and therefore preventing them from swallowing. If they have ingested a foreign body, you might see some traces of it in or around the mouth. Only remove these if you feel comfortable in doing so, or if you're sure it's safe. In all other instances, contact a local vet as soon as possible.

Dental problems

Without proper dental care, plaque and tartar can build up inside your dog's mouth. This can rub against the inside of their lips, causing them to drool more than usual. Poor dental hygiene can also lead to tooth decay, gingivitis, mouth ulcers, and even tumours, all of which can cause excessive drooling. So check your dog's teeth for any discolouration or damage as this can be a sign of periodontal disease. A dog's breath will never smell particularly nice, but dental problems can make it smell much worse.  Any dental issues will need the attention of a vet. In the meantime, focus on prevention. You should be brushing your dog's teeth at least three times a week, and preferably every day.


A salivating dog might have a throat or sinus infection. Other symptoms would include very bad breath, plus a loss of appetite. Dogs are pretty sturdy creatures and most infections will clear up after a few days but you must always contact your vet as they can advise you properly. Your vet may prescribe a short course of antibiotics to kill off the infection, but they will also do thorough checks for other possible causes. Don’t delay if you’re unsure - your dog deserves proper professional care and attention.

Heat stroke

Dogs can't just take their coat off when it gets warm. Certain short-faced breeds, like the Pug or French Bulldog can also suffer from breathing difficulties due to their obstructed airways. Add in some very hot weather, and the dog is at risk of overheating. Excessive drooling is just one of many symptoms. Others include heavy panting, erratic pulse, vomiting, and even collapse. Heatstroke is serious. If your dog is showing any of these signs, get him out of the sun and into an air-conditioned room immediately. You can place your pet on a wet towel and apply tepid water onto his fur and skin. Contact your vet immediately in case your dog needs medical assistance.

Poisonous plants

Dogs will eat almost anything. They're natural scavengers who are always on the lookout for new food sources. Although this helped them survive in the wild for thousands of years, it’s also very risky. They never quite know what they are putting into their bodies, and certain plants and shrubs are poisonous to dogs. Common plants that are bad for your dog include tulips, azaleas, and chrysanthemums. Any dog who eats these is likely to start drooling very heavily, and could also get very sick! You must keep your pet away from these.

Liver or kidney disease

Excessive salivation is also a sign of liver disease or kidney disease. Both can be extremely serious and heavy drooling won't be the only symptom. Other things to look out for include loss of appetite, weight loss, vomiting, and increased urination. Liver and kidney disease are treatable, but early diagnosis and treatment are super important. Take your dog to a vet if you notice any worrying symptoms.


Excess saliva in dogs may also be a sign that they're anxious. What could be causing your dog to feel unsettled? For instance, your dog may drool excessively when you leave the house. In this case, he might be suffering from separation anxiety. By identifying the problem, you can address it and alleviate the symptoms.

Other examples of things which could cause anxiety in a dog include: a fear of loud noises, or a nervousness around new people. But remove or manage the trigger, and the excessive drooling will stop. You can ask your vet to refer you to a clinical animal behaviourist who will help.


Just like humans, dogs salivate when they are feeling nauseous. Nausea could be caused by a variety of problems, including a stomach upset or disease.

Often, nausea occurs due to motion sickness in cars. To treat motion sickness, you will need to desensitize your dog to car journeys. To do this, start with very short car journeys and make them longer over time, as your pet grows in confidence. You should always try to associate a car trip with something positive, by adding something tasty or enjoyable for them to chew or play with in the car. Your dog can be really worried about the movement, noise, smell, and separation from you in the car too, so aim to deal with every aspect of the problem.

If the problem persists, consult a veterinarian, who may be able to prescribe anti-nausea medication for your pet or refer you to a pet behaviourist for behavioural modification help.

Why is my dog drooling in his sleep?

Well, just like humans do, dogs can sleep with their mouths open and this means drool and saliva leaks out. Be sure that your dog doesn’t show any other worrying symptoms first, but then, let sleeping dogs lie.

Why is my dog drooling a lot suddenly?

There’s most likely a medical problem, or your dog is anxious. Check for the above symptoms and possible causes, and if you aren’t sure, contact your vet.

Is it bad if your dog drools?

For some dogs, excessive drooling is completely normal. Unfortunately, you'll just have to get used to it! For other dogs, a little bit of drooling is completely harmless and even necessary. But keep your eyes peeled for any significant changes in your dog’s behaviour. If they're drooling more than usual, or drooling for no apparent reason, then you'll need to identify an underlying cause. Look out for any associated symptoms; think about any recent changes in your dog’s routine or environment, and never be afraid to ask a vet for more advice.

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