160 DISEASES OF THE STOMACH 



HEMATEMESIS. 



Definition.— Hematemesis is the vomiting of blood. It is 

 merely a symptom. The hemorrhage does not always come 

 from the stomach itself, but from structures contiguous to 

 the stomach. In small animals hematemesis is much more 

 common than is usually recognized, but unless large quanti- 

 ties of blood are vomited, it escapes notice. Often scant 

 hemorrhages go unrecognized, the determination of which 

 would be valuable for the diagnosis of some diseases. 



Etiology.— In hematemesis there may be no anatomical 

 lesions on the mucous membrane (diapedesis) ; or the lesions 

 may be very small but numerous and the hemorrhages 

 copious coming from a large surface of the mucosa. On the 

 other hand the Jesion in the mucosa may be quite marked 

 (rhexis; ulcer, etc.) . In the dog hematemesis is quite common 

 and has the following causes : 



Local causes: Ulcerations on the mucosa; erosions on the 

 mucosa; acute and chronic gastritis; tumors; trauma which 

 may be direct (foreign bodies, injury from stomach sound) 

 or indirect (straining during vomiting, stomach operations) ; 

 chemicals (poisons, purgatives, emetics). 



Indirect local causes are further : Obstruction to the portal 

 circulation; pressure on the portal vein; thoracic diseases 

 disturbing circulation; organic heart lesions, etc. 



Hematemesis may occur also from many general causes 

 which produce at the same time hemorrhage from several 

 of the mucous membranes. The following are the most 

 common conditions: Septicemia; autotoxic conditions, 

 uremia, etc.; blood dyscrasias and diseases, hemophilia, 

 scurvy, pernicious anemia, leukemia. The blood may have 

 its origin outside the stomach and come from contiguous 

 abscesses rupturing the stomach wall, or from ulcers and 

 fistulse which may open a suppurating tract into the stomach. 



Hematemesis also occurs during the course of infectious 

 diseases (distemper, rabies). 



Pathology.— The pathological findings depend upon the 

 amount of the hemorrhage. When the hemorrhages prove 

 fatal there is a general pallor of all the viscera; where the 



