In a perfect world, saliva moistens your dog's mouth and stays neatly contained within its enclosure. Problems start though when excessive saliva is produced leading to the buildup of sticky, messy slobber. Drooling often can be explained by looking around at the context for clues. For instance, excitement, nausea or exposure to a bitter or unpleasant tasting substance, might trigger a short-lived episode of drooling, but dogs drool for many more reasons, and in some cases, excessive drooling can signal a potentially serious medical condition.
Natural Born Droolers
Some dogs breeds are prone to salivating excessively, but you can't blame them as it's a matter of conformation. The large, loose jowls dog fanciers find so endearing are the culprits for that steady stream of drool. Dog breeds such as the Saint Bernard, Newfoundland, bloodhound and Neapolitan or English mastiff are prone to drool buckets of saliva. Not much can be done for this type of drooling, other than keeping a drool towel handy at all times.
Russian physiologist Ivan Pavlov couldn't have chosen a better animal than a dog to carry out his studies on the digestive system. Through repeated feedings, his laboratory dogs not only drooled at the sight of food, but started drooling at the mere sight of his assistants -- even when they weren't carrying food. This led to an important scientific discovery concerning associative learning. You won't need a science degree though to understand that dogs drool at the mere sight of food or anything associated with it.
Drooling Over the Car
If your dog is drooling over your fancy sports car, he's likely not envious, rather a tad bit nauseous. Dogs, just like humans, suffer from motion sickness too, the only difference is that they won't turn green or pale; instead, they'll whine, pace and drool, which can get quite messy. The good news is that fortunately most dogs outgrow motion sickness by the time they’re about 1 year old.
An Anxious Pooch
Dog's can't express their emotions through words, but a dribble of saliva can speak volumes in anxious dogs. Puddles of saliva strategically found near doors or windows may be indicative of separation anxiety, a behavior problem seen in dogs who are terrified of being left alone. Drooling also may be observed in dogs who are anxious in other situations such as when exposed to thunderstorms, loud fireworks or when riding in the car.
A Mouthful of Trouble
A horse's mouth can tell a whole lot about the animal's age and health, but so can a dog's mouth. If you notice a bad odor, red, swollen gums and a brownish tint on the teeth, the drooling is likely caused by periodontal disease. A professional cleaning may be needed in this case. However, there's much more. Increased slobber may be seen in dogs with a foreign object stuck somewhere in the mouth, a disorder of the salivary glands, a tooth abscess or an irritated esophagus.
Drooling can be seen in dogs exposed to toxins. A dog could have eaten parts of a poisonous plant, ingested household chemicals or licked toxic toads that go by the name of "Bufo alvarius" and "Bufo marinus." Profuse drooling along with other worrisome symptoms such as lethargy, lack of appetite, trouble breathing, diminished coordination or vomiting, warrant an immediate vet visit.
Another emergency situation is bloat, a potentially fatal condition often affecting deep-chested dogs. Excessive salivation, restlessness, unproductive retching and an enlarged abdomen are some telltale signs of this condition. Heatstroke may cause excessive drooling as well along with panting, red gums and increased body temperature. A vet should be seen immediately as timing is of the essence with both these conditions.