Regurgitation is the relatively
effortless expulsion of undigested food, without retching. It occurs because
the esophagus is physically blocked or because it lacks peristaltic activity.
In either case, the food accumulates until the esophagus is overloaded, after
which the food is passively expelled.
Regurgitation should not be confused with vomiting. Vomiting is the
forceful expulsion of stomach contents, preceded by drooling and retching. The
material vomited is usually sour smelling, partly digested, and stained with
Several bacteria of the salmonella species are capable of producing acute
infectious diarrhea in dogs. Salmonella remain alive for many months or years
in soil and manure. In dogs, the disease is acquired by consuming raw or
commercially contaminated foods, by eating animal manure, or by making oral
contact with surfaces that have been contaminated by the diarrhea of an
infected dog. This bacterial infection is a risk in dogs fed a raw diet, unless
excellent food-handling hygiene is practiced...
The sudden onset of regurgitation in a previously healthy dog
is almost certainly due to a foreign body caught in the esophagus. Constant
drooling indicates that the dog cannot swallow saliva.
Chronic regurgitation (the kind that comes and goes but seems to be getting
worse) suggests a partial obstruction caused by megaesophagus, stricture, or
A serious complication of regurgitation is aspiration pneumonia, in which the lungs
become infected as a result of food being aspirated into them. When
regurgitated food ends up in the lungs, aspiration pneumonia is the result.
Another potentially serious complication is nasal cavity infection. This occurs
when food is regurgitated into the nose.
WebMD Veterinary Reference from "Dog Owner's Home Veterinary Handbook"