Some gastrointestinal (GI) problems (e.g., vomiting, diar- rhea, weight loss, anorexia, icterus, hepatomegaly, abnor- mal behavior associated with eating, abdominal pain) typically necessitate laboratory testing. On the other hand, dysphagia, regurgitation, ptyalism, halitosis, con- stipation, mucoid stools, hematochezia, and melena are usually best approached initially by other means (e.g., physical examination, radiology, ultrasonography, endos- copy, laparotomy, and/or biopsy).
FIGURE 9-3. A, A canine rectal scraping showing a macrophage with numerous engulfed yeasts. These are Histoplasma capsulatum. B, A canine rectal scraping that shows inflammatory cells and spherical organisms with a clear halo. The organisms are Prototheca.
