22 SWINE DISEASES 



emetics, or may be removed by gastric lavage. Objects 

 imbedded in the gastric walls can be removed only by 

 surgical interference, but gastric surgery in swine is not 

 well developed at this time. 



Vomition (Emesis) 



Vomition is rather common in swine and is the result 

 of stimulation of the vomition center, which is located 

 in the medulla. This stimulation may be direct from 

 irritation in the nerve center, but more frequently it is 

 indirect from irritation of some portion of the gastro- 

 intestinal tract. Vomition is therefore a symptom of a 

 variety of disease conditions. It may be caused by 

 engorgement of the stomach, nature having provided 

 this method of relieving an overloaded stomach. In- 

 testinal obstruction is another frequent cause of vomition 

 in swine, as is also irritation of the mucosa of the eso- 

 phagus, intestine, and more especially the stomach. 

 Thus hog cholera is frequently evidenced by vomition. 

 Gastric parasites not infrequently cause sufficient irri- 

 tation to produce violent vomition, particularly in small 

 pigs, while chemical irritants acting upon the digestive 

 mucosa may produce vomition. 



Swine as a rule vomit easily. The affected animals" 1 

 become uneasy and restless. They extend the head and 

 depress the nose, the esophageal muscles are relaxed, 

 the abdominal muscles contract, and the stomach con- 

 tent is thus forced out. The vomited material usually 

 consists of particles of food admixed with mucus, although 

 it may be composed entirely of a thin, shiny mucus. 

 The expelled material may contain intestinal as well as 

 gastric contents. 



Anemia 



Anemia of the mucous membrane of the stomach 

 occurs in swine after surgical operations in which large 

 quantities of blood have been lost. It may also be 

 due to obstruction of the arteries supplying the gastric 

 walls. 



