Dogs will commonly drool when they are feeling nauseous. It’s often a precursor to vomiting. Whether it was the rotting chicken carcass they stole out of the garbage when you weren’t looking or motion sickness during a car ride, nausea will cause their body to produce more saliva. If they are experiencing motion sickness, they will also likely pant more than usual.
Dental Disease or Oral Mass
Excessive bacterial build-up in the mouth leads to gingivitis and periodontal disease. Inflamed gums and infected teeth are painful and can cause your dog to drool. Similarly, if your dog has lumps, bumps, or growths of any kind in their mouth, they can also contribute to drooling.
Sometimes our four-legged friends get things stuck in their mouths, such as a stick or a piece of a toy. These foreign objects can get lodged between teeth or stuck across the roof of their mouth, which can result in drooling.
Noxious Ingestion or Toxicity
Sometimes dogs are too curious for their own good. Licking or eating substances that are toxic, poisonous, or even just overly bitter will cause your dog to drool substantially. This includes household cleaners, human medications, plants – the list goes on.
Pro Tip: Sometimes drooling in dogs is simply a normal behavioral response to food or due to breed-specific anatomy of their mouth (such as Bulldogs and Mastiffs).
Some dog breeds are known to drool more than others due to their specific anatomy. Breeds such as St. Bernards, Mastiffs, Bloodhounds, and Bulldogs are all natural droolers due to the shape of their mouth, their long jowls, and excess skin around their mouth that don’t do a very good job keeping saliva inside the mouth.
Just like humans, dogs will salivate when they see or smell their favorite food (or in some cases, when they know it’s dinner time). This is a completely natural response, although it may force you to clean your floors more often than you would like.