In response to the post that appeared a couple of weeks ago on the importance of differentiating between vomiting and regurgitation, reader ASDMarlene asked for some more information about why this distinction is so important. Perhaps the best way for me to demonstrate this is to show what complete work-ups for these conditions might look like.

In both cases, I’d start with a history and physical examination, but from there the tests that I might run are very different. Of course, every patient doesn’t need all or even most of the tests listed (and some might require other tests that I didn’t mention) but the following are examples of what might be involved if an owner wants a definitive answer to what is causing a dog’s regurgitation or vomiting.

Regurgitation

• neurological exam
• chest X-ray
• esophagraphy (i.e., taking a series of X-rays after a dog has swallowed a radio-opaque substance)
• esophagoscopy (i.e., using an endoscope to examine the inside of the esophagus)
• blood chemistries and other tests for specific conditions if warranted
• electromyelogram (i.e., an electrical recording of muscular activity)
• muscle and nerve biopsies

Acute Vomiting

• parvovirus testing
• distemper testing
• evaluate drug/toxin exposure (e.g., NSAIDS, steroids, lead, zinc, insecticides)
• dietary history (e.g., for foreign bodies, dietary indiscretion, or a recent change in diet)
• abdominal X-rays
• abdominal ultrasound
• complete cell count, blood chemistry, urinalysis, fecal examination, heartworm test
• endoscopic exam of the upper gastrointestinal tract
• barium swallow (i.e., a series of X-rays taken after a dog swallows a radio-opaque substance)
• exploratory abdominal surgery

You can see that only a few tests show up in both lists. Therefore, if a veterinarian starts heading down the wrong track, he or she can end up wasting a lot of time and money pursuing a diagnosis for the wrong condition.

The reason why the tests a veterinarian might run for regurgitation versus acute vomiting are so dissimilar is because the conditions’ potential causes are also very different. For example, my list of differential diagnoses for regurgitation might include an esophageal foreign body, a mass that was pressing on or otherwise obstructing the esophagus, an esophageal stricture, myasthenia gravis, an esophageal motility disorder, idiopathic megaesophagus, hypothyroidism, hypoadrenocorticism, polymyositis, or polymyopathy. On the other hand, possible causes for acute vomiting include parvovirus, canine distemper, drug or toxin exposure, recent dietary changes, dietary indiscretion, foreign body ingestion, gastric dilation and volvulus, pancreatitis, renal failure, diabetes mellitus, liver disease, pyometra, intestinal parasites, inflammatory bowel disease, gastrointestinal cancer, and many, many more.

As for ASDMarlene’s dog that has either vomited or regurgitated twice after eating chicken feed, I suspect her presumption that it was caused by the dog wolfing down the grain is correct. In the absence of the problem occurring under other circumstances, I doubt it is anything to worry about … just her body’s way of saying, "Whoa there sister, I think eating that might have been a big mistake."

Dr. Jennifer Coates

Image: Tyler Olson / via Shutterstock