250 Dilatation of the Rumen. 



animals are most commonly attacked, more rarely cattle on 

 jDasture. 



Etiology. The affection is usually due to the ingestion of 

 iiniisnally large masses of feed; it is immaterial whether the 

 food is of the highest quality or unsuitable in character. If 

 the animals obtain palatal)le hay, green feed, flour or grain 

 feed without restriction, or if they have broken loose, they 

 are liable to overfeed, particularly if they had been starved 

 for some time. (There are some countries in which it is 

 customary to increase the live weight of animals to be sold for 

 slaughtering by feeding them excessive quantities of feed 

 before the transfer is made.) Animals occasionally overfeed 

 on rich pastures, particularly if they have been fed sparingly 

 in the barn. The affection is also brought about by feeding 

 with voluminous feed which is too dry or improperly prepared 

 (chaff, straw, coarse clover, hay, etc.) ; a low nutritive value 

 causes the animals to ingest great quantities. Beets, leaves of 

 beets and potatoes, particularly in a boiled mushy condition, 

 kitchen garbage, distillers' or brewers' mash, mouldy or frozen 

 feed may likewise cause dilatation of the rumen. Finally, lack 

 of water (due to neglect) during dry feeding, becomes respon- 

 sible for the disease. 



Predisposing factors sometimes act as contributor^^ causes, 

 such as physical weakness, continuous stay in the stable, inges- 

 tion of too cold water, prevention of mastication by overexertion 

 after feeding, sudden change from green to dry feeding. 



Cadeac holds that dilatation of the rumen as well as acute bloating of rumi- 

 nants always follows a preliminary paresis of the rumen, so that the former are 

 always secondary conditions. Numerous observations however show that an excessive 

 ingestion of food may bring aliout the affection in animals with a rumen functioning 

 a1)solntely normally. One is justified in drawing the conclusion that a normally 

 <leveloped and normally functioning niuscularis of the rumen cannot be stretched 

 beyond a reasonable limit. 



There is, however, no doubt that the rumens of different individuals differ 

 as to the power of its niuscularis, and that external conditions may exert a goo 1 

 deal of influence. 



Eber looks upon dilatation of the rumen as a type of idiopathic paresis of 

 the rumen in contradistinction to sympathetic paresis of the rumen due to organic 

 affections of the different parts of the stomach and of the neighboring organs. 



Pathogenesis. After the effects of one of the enumerated 

 etiologic factors have become manifest, there exists an improper 

 relation between the mass and weight of the ingested food and 

 the ability of the rumen to the detriment of the latter. The 

 consequence is that the masses of feed present in the rumen 

 are not properly mixed and moved, or not at all, in spite of 

 the fact that the muscularis is stimulated to powerful contrac- 

 tions. The contents of the rumen then swell more or less and 

 develop, in consequence of fermentative processes, an abundance 

 of gas. The more juicy the feed has been, the more rapidly 

 and the more abundantly gas forms. If the feed has been too 

 dry, gas is not formed at all, or a small amount only is formed 



