Hematemesis is the vomiting of blood. There are many causes of this condition. The source is generally upper gastrointestinal tract or there may be a disruption in the lining of the tube connecting the mouth and esophagus or an irritation of the stomach or intestines which can lead to inflammation, bleeding and eventually, the expulsion of blood through vomiting. Alternatively, the blood may originate from an inflammation or injury in the mouth or lungs, after which it is swallowed and then thrown up.
This condition is relatively common in dogs and can affect a wide range of systems. Trauma, ulcer, inflammation or the presence of a foreign object can affect gastrointestinal system. Heart murmur and/or low blood pressure can be due to hemorrhage affecting the cardiovascular system. Abnormally fast breathing is also due to hemorrhage. A clotting disorder (coagulopathy) can lead to hemorrhage in the stomach or intestines, and can also lead to hematemesis.
Primary symptom is the presence of blood in the vomiting. Blood can appear as fresh blood, formed clots, or digested blood which resembles coffee grounds. Lack of appetite, abdominal pain and tarry stool are other indicative symptoms for this condition.