DISEASES OF THE STOMACH. 209 



phuretted and carburetted hydrogen, are also occasionally set 

 free. Flatulence of this kind is probably due to alteration in 

 the quality of the gastric juice, to feeble movements of the 

 stomach and intestines, and to pyloric or intestinal ob- 

 struction, which, by retaining the food and impeding the 

 process of digestion, favour fermentative and putrefactive 

 changes. 



Vomiting, orEmesis. — The rarity of vomiting in the horse 

 has been attributed, firstly, to its small susceptibility to the 

 action of nauseants ; and, secondly, to the supposed difficulty 

 attending the process from the anatomical conformation of 

 the stomach in the horse. It is well known that the mucous 

 membrane is gathered in folds or ruga3 around the cardiac 

 opening, and thus the food is prevented from escaping into 

 the oesophagus. 



Vomiting in the horse chiefly depends on reflex irritation, 

 due to functional or organic diseases of the stomach. The 

 ejected matters are chiefly expelled through the nostrils. 



Vomiting has been observed in cases of gastric distension, 

 and Eobertson mentions some cases of young horses in which 

 sickness was induced by eating haws. Some of these cases 

 proved fatal, and in others marked prostration for several days 

 followed the vomiting, which was attended with great distress. 

 Vomiting also occasionally results from the injection of certain 

 poisons, administered wilfully or with good intention. Every 

 case of hellebore poisoning which we have been called upon 

 to treat has been attended with nausea and several with 

 actual vomiting. 



Lastly, vomiting occurs in cases of rupture of the stomach, 

 and has been noticed when there was dilatation of the lower 

 jmrt of the oesophagus close to its opening into the stomach. 



The treatment of emesis will vary in accordance with the 

 disease with which it may be associated, under which it will 

 be again referred to. 



U 



