DIGESTIVE APPARATUS. 145 



organ in other animals) and the large fundus of the horse's 

 stomach must be considered in this connection. 



A vigorous contraction of the stomach will serve to over- 

 come these obstacles and vomiting may occur in the horse. 

 In such cases, however, there is always danger of rupture, of 

 the organ. This is the usual result when the stomach is well 

 filled with food. Vomiting in the course of colic is therefore 

 always a serious symptom. If. hozvcvcr. tJic stomach of the 

 Jiorsc is moderately filled zcith fluid contents, a rupture need 

 not occur. In such cases the act of vomiting is usually not 

 caused by an overloaded stomach but by direct stimulation of 

 the vomiting center. (Chloroform narcosis, hemorrhages and 

 inflammations near the medulla). 



Vomiting is a 1 w a \' s a s y m p t o m of d i s - 

 ease and occurs under the following conditions : 



a. During the presence of foreign bodies in the larynx 

 or at the base of the tongue : pieces of bone, fish bones, 

 needles, feathers, etc.. also when tough, stringy mucus col- 

 lects in this region in the course of pharyngitis and laryngitis. 



b. Obstruction of esophagus. 



c. Gastric affections, overloading of stomach, gastritis, 

 and in certain poisonings. 



d. Intestinal affections, such as prevent the normal 

 progress of food masses through the lumen of the intestine 

 and thus provoke antiperistaltic movements which cause the 

 stomach to become distended with intestinal contents, irrita- 

 tion of its mucous membrane, and vomiting. 



The character of the vomited material may often serve to 

 determine the cause of the act and the origin (stomach or in- 

 testine) of the ejected mass. 



VI. The Abdomen. 



Examination of the abdomen is conducted according to 

 the following general rules. 



a. Inspection. The volume or circumference of the 



