David C. Twedt, DVM, Diplomate ACVIM, Colorado State University

It is important to determine whether the patient is actually vomiting and to obtain a detailed vomiting, drug, and diet history. Questions regarding the vaccination status of the animal; travel history; previous medical problems; and if there are any concurrent signs that may occur with systemic or metabolic disease, such as polydipsia, polyuria, or weight loss, are of value. Information gathered about the actual vomiting episodes should include duration, frequency, association with eating or drinking, character of the vomitus, and treatments that have been given. Gastric disorders can be grouped into conditions of mucosal involvement, those causing gastric outflow obstruction, and gastric motility disorders. Inflammatory gastric mucosal disorders most commonly include lymphocytic-plasmacytic, eosinophilic, or granulomatous gastritis, and are diagnosed by biopsy. Conditions causing gastric outflow obstructions most often are associated with gastrointestinal foreign bodies or neoplasia. Most gastric motility disorders result in delayed gastric emptying with gastric retention and vomiting. Vomiting of a meal more than 10 hours after eating is suggestive of a gastric retention disorder. Animals with mild signs and minimal debilitation should first have dietary manipulation with food trials and treatment for gastrointestinal parasites. Animals suspected of having food-related reactions should be fed a hypoallergenic diet for at least a 2-week trial. Diagnostics in severe cases or in patients that have chronic vomiting should include a minimum database (CBC, biochemical profile, and urinalysis), fecal examination, and abdominal radiographs. An in-depth gastrointestinal evaluation should be considered with significant or severe gastric or gastrointestinal disease or in the patient that has not responded to adequate dietary and anthelmintic therapy. Radiology should be performed when a gastric lesion, foreign body, or outflow obstruction is suspected. A double-contrast gastrogram provides good mucosal delineation and identifies intraluminal foreign bodies or lesions. If no gastric lesion is identified, additional barium then can be given for a standard upper gastrointestinal study. Barium mixed with food seems to be a better test of gastric emptying for disorders of motility. As a rule, barium mixed with a standard meal should empty by 8 to 10 hours.

COMMENTARY: Although vomiting is a protective mechanism, it can also be indicative of other problems, such as gastrointestinal, systemic, or metabolic disease. A strategic approach to the vomiting patient is critical, as severe vomiting can result in volume depletion, acid-base and electrolyte imbalance, esophagitis, aspiration pneumonia, and malnutrition. The history, physical examination, and basic laboratory findings are pertinent to guiding the clinician to a diagnosis or further diagnostic tests. In cases of severe or chronic vomiting, in-depth laboratory diagnostics are required, including CBC, biochemical profile, urinalysis, fecal examination, and abdominal radiographs. If the results of these initial tests are normal, further in-depth diagnostics, including contrast studies, ultrasound examination, and endoscopy, may be required before a diagnosis can be made and appropriate treatment implemented.