172 INDIGESTION. 



health, and particularly on the nervous system, thus favouring organic 

 fermentations. 



Symptoms. The earlier symptoms of indigestion escape observation, 

 but they soon begin to develop rapidly, and are then very easy to follow. 

 They always exhibit the same characters, developing, however, with 

 more or less rapidity in diftei-ent cases. Soon after they commence 

 feeding animals appear to experience special discomfort, which causes 

 those at grass to stop grazing ; even when stabled they stop feeding. 

 From this time they show eructation, repeated yawning, restlessness, 

 and some anxiety. 



In a quarter of an hour, or less, the left liank begins to project, both 

 laterally and vertically, so that eventually the walls of that part of the 

 abdomen may project above the transverse processes of the lumbar 

 vertebrae. The right flank also becomes swollen, as a consequence of 

 the intestine being thrust out of position. The animal very rapidly 

 shows general disturbance ; the nostrils are dilated, the mucous mem- 

 branes congested, respiration becomes rapid, and asphyxia threatens. 

 The respiration soon becomes panting, for the distended rumen para- 

 lyses the diaphragm and compresses the lungs. To ease respiration 

 the animals open the mouth, extend the neck, and stand with the 

 front limbs spread apart; but this fails to prevent dyspncea l)ecoming 

 more intense and asphyxia imminent. 



The heart beats more rapidly, the superficial veins appear swollen, 

 and the mucous membranes cyanotic. The rhythmic contractions of the 

 rumen can no longer be detected by manual examination of the left 

 flank ; and on auscultation one neither hears the liquid nor the rolling 

 sound, but only exaggerated crepitation. Finally, there is marked 

 tympanitic resonance on percussion. 



In cases of very grave tympanites the gaseous pressure in the 

 interior of the rumen appears to stop the crepitation sound. The 

 animals soon become unable to walk or even to move, suddenly fall 

 to the ground, and die rapidly from asphyxia. 



The rapidity with which gaseous indigestion develops varies greatly. 

 Sheep and oxen may die from tympanites, within an hour or even half 

 an hour of their arrival in the field ; but more frequently the symptoms 

 develop slowly, only becoming alarming after some hours and continuing 

 for twelve or even twenty-four hours without causing death. 



As a rule, the gas is voided by a series of eructations which empty the 

 rumen, and recovery follows ; but when distension is extreme eructation 

 cannot occur, and gaseous indigestion then ends in asphyxia and death. 



Lesions. It might be imagined that this form of indigestion would 

 only appear when the rumen contains a large quantity of food ; but, 

 in point of fact, the rumen often contains very little. 



