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50 CHRONIC VOMITING IN CATS PEER REVIEWED of infectious and traumatic diseases decreases. 9 Cats with outdoor access often have greater exposure to parasites and retroviruses, although all cats should be considered at risk. Although these trends can help guide the formation of an appropriate initial diagnostic plan, atypical presentation is possible. Cats with chronic vomiting should be assessed for the changes listed in Box 1 . Polydipsia with polyuria should be differentiated from polydipsia in the absence of polyuria. The latter can result from increased GI water loss, which is not always accompanied by diarrhea. Fecal scoring charts should be reviewed with clients to determine fecal consistency. If present, diarrhea should be categorized (small, large, or mixed bowel) and the presence of blood determined. Weight loss should be subdivided into changes to fat stores, muscle mass, or both. If GI disease is diagnosed, the feline chronic enteropathy activity index should be calculated to quantitate the severity of disease, 10 thereby facilitating more accurate evaluation of the patient's response to therapy. PHYSICAL EXAMINATION Although physical examination is often unremarkable in cats with chronic vomiting, abnormalities can aid in winnowing the differential list. Cats with chronic GI disease are typically euvolemic but can have decreased skin turgor due to dermal aging changes or depletion of fat stores. Conversely, oral mucous membranes can be moist in dehydrated cats because of ptyalism. The nictitans, sclera, and mucous membranes should be carefully assessed for jaundice. The base of the tongue should be elevated to check for linear foreign bodies, particularly in younger cats and cats with a history of pica. The breath should be checked for uremic halitosis and the mouth surveyed for periodontal disease, calculus, ulcers, and masses. Complete ophthalmic evaluation might reveal anterior uveitis, chorioretinitis, vascular tortuosity, or retinal hemorrhage. The ventral neck should be carefully palpated for thyroid nodules. Abnormalities on thoracic auscultation or abdominal palpation might alter initial testing. The thorax should be auscultated for cardiac murmurs, rhythm disturbances, and abnormal bronchovesicular sounds. Gentle but thorough abdominal palpation might reveal nausea (licking of lips, excessive swallowing, resistance to palpation), hepatomegaly, cranial abdominal pain, irregularity or asymmetry of the kidneys, an enlarged urinary bladder, or peritoneal effusion, increasing prioritization of abdominal imaging. Careful attention should be paid to GI abnormalities, such as diffuse thickening or mass effects. Rectal temperature should be determined regardless of patient temperament; alterations such as hypothermia and fever generally suggest systemic disease. Hematochezia or melena might be identified on inspection of the thermometer or sedated rectal examination. INITIAL DIAGNOSTIC TESTS As noted above, the diagnostic approach for each case should be customized after assessment of the patient's history, physical examination findings (including metabolic stability), and differential diagnosis. The typical baseline diagnostics are discussed below. Although a second-tier test for most cases of chronic vomiting, abdominal radiography might be the initial diagnostic test performed when obstruction or an abdominal mass effect is suspected. Fecal Flotation/Empirical Deworming Fecal flotation and empirical deworming should be performed in all cases, regardless of outdoor exposure. A minimum of 2 g of feces, a solution with a specific gravity greater than 1.240, and centrifugation should be used for fecal flotation to decrease the likelihood of false- negative results (by up to 10-fold for some parasites). 11 BOX 1. Pertinent Historical Changes in Cats With Chronic Vomiting • Activity level and appetite • Water intake • Urine output • Fecal consistency • Weight • Body and muscle condition score (eg, client reports that the cat is "hollow in the belly" or "skinny") • Demeanor and activity, (eg, hyperactivity, irritability, pruritus, excessive vocalization)