ACUTE METEOBISM OF RUMINANTS. 



107 



composition of this mixture varies in différent cases of tympanites. 

 Keiset has found the following composition in a cow which was 

 meteorized, in a clover field, the animal having died two hours 

 before : 



Carbonic acid 74 per cent. 



Carburet of hydrogen ........ 24 



Nitrogen .......... 2 " 



The same author has found 76 per cent, of carbonic acid in a 

 meteorized sheep. Sulphuretted hydrogen does not appear in this 

 analysis, which must be looked upon as pure chance, for this gas is 

 one of the products of normal decomposition of albumen in the 

 rumen. 



The overdistention of the rumen may cause its rupture and some- 

 times that of the diaphragm ; in such cases the alimentary matters 

 and gases escape into the abdominal cavity, but the very rapid 

 course of the disease does not allow peritonitis to develop. 



The veins of the skin, those of the subcutaneous connective 

 tissue, and the large venous trunks (jugular, etc.) are filled with a 

 dark blood which becomes oxidized when in contact with air. The 

 lungs are hyperemic and present sub-pleural and parenchymatous 

 extravasations; at times we observe œdema of the lungs. The 

 parietal pleura is raised by injected blood, especially in the superior 

 regions of the thorax. The right auricle and the right ventricle 

 are greatly distended by the blood ; the coronary veins are injected; 

 the pericardium and the endocardium are marked with ecchymoses; 

 we may exceptionally observe rupture of the right heart. The 

 intestinal mucous membrane is congested ; we observe hemorrhages 

 into the submucous and subserous connective tissue. Anacker has 

 pointed out laceration of the vessels of the spleen and the destruc- 

 tion of its tissue. The mucous membranes of the head, the cerebral 

 meninges, and the sinuses are congested ; sometimes we find apo- 

 plectic centres in the brain. 



Symptoms. The most striking symptom is the sudden increase 

 and the great volume of the abdomen ; the left flank may extend 

 so greatly as to become level with the dorsal spine; some cases 

 are encountered where it even goes beyond this. The abdominal 

 walls are much strained and very elastic ; the percussion gives a 

 clear tympanic, even metallic sound ; the normal bruit of the rumen 

 has disappeared. 



From the first onset the animals ordinarily cease to feed, and 



