628 RurxuRE of the stomach. 



them when, after a full meal, they have at once been put to 

 continuous and severe labour : the reason of this seems to be 

 that the steady pressure of the collar over the oesophagus pre- 

 vents the eructation and escape of the rapidly generated gases 

 arising from the softening and maceration of the contained 

 food. The lesion may take place by steady pressure from within, 

 without much exhibition of uneasiness or pain ; so that when 

 seen by the professional attendant, the rupture having, been 

 accomplished, the attractive symptoms of abdominal pain are 

 indicative rather of further peritoneal and visceral inflammation 

 than of rupture of the stomach itself At other times it occurs 

 during the course of gastric disturbance and bowel complica- 

 tions, the rupture taking place during and in consequence of 

 the violence of the animal's struggles ; in such cases the symp- 

 toms already existing are further aggravated or modified. 



There may, previous to the rupture, have been no inflam- 

 matory action, which may only date from and be consequent 

 on the occurrence of the lesion, the antecedent condition being 

 merely that of uneasiness and pain, the result of extreme dis- 

 tension. 



Although this lesion of rupture of the walls of the stomach 

 may take place with an animal in which the organ is per- 

 fectly healthy, there are fair grounds for believing that in 

 many the viscus has, previous to the fatal lesion, been re- 

 peatedly the seat of derangement and distension, and where 

 the rupture can only be regarded as a natural sequel of chronic 

 indigestion. In such cases the walls of the organ have become 

 not only attenuated by the continued stretching process to 

 which they have been subjected, but the muscular tissue of 

 which they are made up may have become somcAvhat altered 

 in its elementary structure. 



So far, corroboration of the statement that textural alteration 

 is an important item in the production of the lesion is the fact 

 that it rarely takes place in the young animal, that the aged, 

 exhausted, and hard- worked arc its most frequent subjects. 



Symptoms. — The indications of this lesion, although in many 

 cases sufliciently well marked, are not in all such as to leave 

 no doubt of its existence on the mind of the observer. Vomi- 

 tion, or attempts at vomition — an act of rare occurrence in the 

 horse — have often been regarded as specially diagnostic of 



