A place like the Right Livers' Rest was bound to draw freaks, same as molasses draws flies. 1935, George Goodchild, chapter 5, in Death on the Centre Court: By one o'clock the place was choc-a-bloc.
Respiratory infections as well as infections of certain glands can be a cause of excessive saliva, according to the National Library of Medicine. Children with a cold, influenza or nasal allergies may have excessive saliva and drool.
There are many different causes for excessive salivation. You will need to give a thorough history of your dog's health, including vaccination status, current medications, possible toxin exposure, a background history of symptoms, and any other possible incidents that might have precipitated this condition.