CHAPTER III. 

 DISEASES OF THE STOMACH AND BOWELS. 



VOMITING. VOMITION. 



Definition. — ^The forcible ejection of the contents of the 

 stomach through the esophagus and mouth or nose. 



Occurrence. — ^Vomiting is a symptom and not a disease. 

 It occurs frequently in carnivorous animals but is rare in 

 herbivorous. Horses seldom vomit and when they do it 

 commonly indicates rupture of the stomach. True vomiting, 

 the ejection of the contents of the abomasum, in the adult 

 ox and sheep is so rare as to be denied by some authorities; 

 the regm-gitation of paunch contents, however, quite common. 



Vomiting may have either a central or a peripheral origin. 

 The formar is due to some disturbance acting directly upon 

 the vomiting center in the medulla oblongata (central vomi- 

 tion), and the latter to an irritation of peripheral nerves, 

 usually of the pharynx or stomach, which reflexly stimulates 

 the vomiting center (reflex vomition) . In animals vomiting 

 is usually reflex. It is one of Nature's efforts at self-healing, 

 not only removing indigestible or deleterious material from 

 the stomach, greatly to the relief of the patient, but at the 

 same time, being a complex phenomenon, exerts a beneficial 

 effect upon many other organs, provided, of course, the vomi- 

 tion is not continued too long. 



Etiology. — Reflex vomition most commonly is caused by: 

 (a) Overloading of the stomach; (b) irritation of the stomach 

 by irritant foods or certain drugs (emetics); (c) gastric 

 catarrh; (d) gastric parasites; (e) foreign bodies in the 

 stomach; (/) occlusion of the pylorus or in ruminants of the 

 openings between compartments of the stomach (tumors, 

 foreign bodies); (g) stoppage of the intestines (dislocation 

 of bowel, tumors, foreign bodies) ; (h) acute peritonitis, either 



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