Is My Dog Vomiting or Regurgitating?
Boomer, an adorably effervescent, young Cairn Terrier, was referred to me for vomiting three days in a row. This mischievous little boy raided the kitchen garbage the day before the vomiting began. Neither blood work nor abdominal X-rays, performed by the referring veterinarian, provided a diagnosis. When I questioned Boomer’s family, I learned that their dog was bringing up clear fluid after drinking, and undigested food after eating. Additionally, none of the retching that dogs typically do right before vomiting had been observed. This history provided some big clues that redirected my thinking. Boomer was likely regurgitating rather than vomiting.
Vomiting occurs when food or liquid is expelled from the stomach or upper small intestine; it’s preceded by some audible retching (no different than when a person is nauseated and hovering over the toilet). The vomited material may be food that appears undigested or partially digested, clear liquid (if it originates from the stomach), yellow or green liquid or semisolid matter if it originates from the small intestine where bile is secreted.
Regurgitation differs from vomiting in that the expelled material almost always originates from within the esophagus—the muscular tube that propels food, water and saliva from the mouth down into the stomach. The regurgitated material consists of water, saliva, or undgested food that comes spewing forth without any audible retching or warning. Regurgitation typically takes the dog and anyone in close proximity completely by surprise.
Because the event is so sudden, the larynx (the opening to the windpipe) may not have time to close, and some of the regurgitated material can be inhaled into the lungs. This results in a serious condition called aspiration pneumonia and is usually associated with an abrupt onset of coughing and labored breathing.
The importance of differentiating vomiting from regurgitation
So, why is it important to differentiate whether my patient is regurgitating or vomiting? Here’s the reason why. The tests for determining the cause of regurgitation are different than those used to determine the cause of vomiting. And the more wisely diagnostic tests are selected, the more expediently a diagnosis is established (better for the patient as well as the client’s pocket book). Diagnostic testing for regurgitation involves evaluation of primarily the esophagus and sometimes the stomach. Evaluating the vomiting patient involves evaluation of the stomach and small intestine along with screening for other diseases such as