How I approach... The vomiting cat

Vomiting, alone or in combination with other clinical signs, is a common presenting complaint in cats; in this paper the authors share their recommendations for a systematic clinical approach for both acute and chronic vomiting cases.

An introduction to the vomiting cat

Both acute and chronic vomiting can be the manifestations of primary gastrointestinal (GI) disease or extra-GI conditions in the cat. The list of potential differential diagnoses for vomiting is extensive, and other criteria from both the history and physical examination, followed by appropriate laboratory and diagnostic imaging tests, can often help to narrow those down. For acute vomiting, the two most important decisions to be made following initial triage are to decide if relatively swift supportive care (particularly replacement of fluid losses and correction of electrolyte or acid-base imbalances) is needed, and if surgical intervention may be necessary (which could be diagnostic, therapeutic or both) when stabilization is achieved. Once the patient is cardiovascularly stable and there is no immediate indication for surgery, a more complete list of differential diagnoses for acute vomiting can be considered (Table 1).

For chronic vomiting, consideration of possible causes and diagnostic tests can usually be at a slower pace, and can depend on any additional presenting complaints, physical examination findings, and (not uncommonly) an owner’s preferences. It seems reasonable to assess more common conditions first and to proceed from there in a stepwise manner. For a cat with chronic GI signs and no evidence of extra-GI or infectious disease, the two most common remaining differential diagnoses are idiopathic Inflammatory Bowel Disease (IBD) and Low-Grade Alimentary Lymphoma (LGAL), and more invasive tests (e.g., biopsies) are commonly performed relatively early in the diagnostic workup compared to dogs. This article will describe a stepwise diagnostic approach for cats presented with either acute or chronic vomiting, and discuss management of the more common underlying conditions.

AKI = acute kidney injury, GIST = gastrointestinal stromal tumor, NSAIDs = non-steroidal anti-inflammatory drugs, UTI = urinary tract infection

Key aspects – signalment and clinical history

A complete clinical history is extremely useful to refine the list of differential diagnoses. It is particularly important to establish that the owner does not describe regurgitation, retching or even coughing instead of vomiting, as these can be difficult to distinguish from one another in cats. Once it is established to be vomiting, the respective signalment and the presence or absence of additional clinical signs can help prioritizing some conditions over others. Therefore, the clinician should consider:

Age and breed

Cats with dietary indiscretions, food hypersensitivities or food-responsive chronic enteropathies (FRE) tend to be younger than those with other conditions, especially other forms of chronic enteropathies (CE) 1. Conversely, hyperthyroidism is a common cause of chronic vomiting, as is neoplasia, with both being more likely in older cats. Siamese cats are at an increased risk of GI adenocarcinoma 2, whilst longhair breeds are more likely to have trichobezoars, which can lead to partial or complete GI obstruction.

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