Page 425 - Small Animal Internal Medicine, 6th Edition

CHAPTER 26 Clinical Manifestations of Gastrointestinal Disorders 397

and cats with pancreatitis may have normal immunoreac- trauma secondary to vigorous vomiting from any cause, and
tive pancreatic lipase activities and normal abdominal ultra- animals with such “hematemesis” should generally be treated
VetBooks.ir sound examinations; and Physaloptera infections are almost as described in the previous section on vomiting. Patients
that produce more substantial amounts of blood generally
never diagnosed by fecal examination. Finally, the clinician
may have to consider uncommon diseases that are more
usually caused by gastroduodenal ulceration and erosion
difficult to diagnose (e.g., idiopathic gastric hypomotility, should be approached differently. Although hematemesis is
occult CNS disease). (GUE), clinicians should not make this assumption and
automatically treat for such. The clinician should first check
HEMATEMESIS the hematocrit and plasma total protein concentration to
determine whether a blood transfusion is necessary (see Fig.
Clinicians must often use history and physical examination 26.3). The clinician should next try to determine whether
to help identify hematemesis as well as distinguish it from there is a coagulopathy (uncommon but important), inges-
other problems. Hematemesis is expulsion of digested (i.e., tion of blood from another site (including the respiratory
“coffee grounds”) or fresh blood. Animals with oral lesions tract), or a gastrointestinal tract (GIT) lesion (e.g., GUE)
that have blood dripping from their lips do not have (Box 26.7). Platelet counts and a measure of clotting capabil-
hematemesis. Likewise, hemoptysis (i.e., coughing up blood) ity (e.g., buccal mucosal bleeding time) are strongly recom-
is not hematemesis. mended. The clinician should next look for obvious causes
Clinicians should distinguish vomiting that produces of GIT hemorrhage (e.g., acute gastritis, acute hemorrhagic
specks of blood from vomiting in which there is substantial diarrheal syndrome [used to be called hemorrhagic gastroen-
blood present. The former may be caused by gastric mucosal teritis], or GUE due to ulcerogenic drugs [e.g., nonsteroidal

BOX 26.7

Causes of Hematemesis

Coagulopathy (Uncommon) Other causes
Thrombocytopenia/platelet dysfunction • Hepatic disease (common and important)
Clotting factor deficiency • Hypoadrenocorticism (uncommon but important)
Disseminated intravascular coagulation • Pancreatitis (common disease but uncommonly
causes ulceration or hematemesis)
Alimentary Tract Lesion • Renal disease (common disease but uncommonly
Gastrointestinal tract ulceration/erosion (common and causes ulceration or hematemesis)
important) • Inflammatory diseases
Infiltrative disease (important) Foreign objects (rarely a primary cause of hematemesis,
• Neoplasia but will worsen preexisting ulceration or erosion)
• Leiomyoma Gastritis
• Carcinomas Acute gastritis (common)
• Lymphomas Acute hemorrhagic diarrheal syndrome (common)
• Pythiosis (especially younger dogs in the Chronic gastritis (uncommon in dogs)
southeastern United States) Helicobacter-associated disease (doubtful association
• Inflammatory bowel disease (uncommon) with hematemesis in dogs and cats)
“Stress” ulceration Gastric mucosal trauma from vigorous vomiting*
• Hypovolemic shock Gastric polyps
• Septic shock (i.e., systemic inflammatory response Esophageal disease (uncommon)
syndrome) Tumor
• After gastric dilation or volvulus Severe esophagitis
• Neurogenic “shock” Trauma
• Extreme or sustained exertion (common in select Bleeding oral lesion
working animals) Gallbladder disease (especially tumors) (rare)
Hyperacidity Extraalimentary Tract Lesion (Blood Is Swallowed and
• Mast cell tumor Then Vomited) (Rare)
• Gastrinoma (rare)
Iatrogenic causes Respiratory tract disorders
• Nonsteroidal antiinflammatory drug (common and Lung lobe torsion
important) Pulmonary tumor
• Glucocorticoids (especially dexamethasone) Posterior nares lesion
(important) Dietary indiscretion
*Hematemesis caused by vigorous vomiting usually consists of specks of blood as opposed to larger quantities.