Overloaded {Impacted') Rumen. 109 



come from the paralyzing products of fungi or bacteria in musty- 

 fodder or of such chemical poisons as. lead, and the cyanides. 



A catarrhal affection of the rumen, and the congestion pro- 

 duced by irritant plants, green food with an excess of chlorophyl, 

 and the whole list of irritants and narcotico-acrids, will weaken 

 the first stomach and predispose to overdistension. 



Anything which lessens the normal vermicular movements of 

 the rumen and hinders regurgitation and rumination tends to im- 

 paction, and hence an aliment which is to a large extent fibrous, 

 innutritious, and unfermentable, such as hay from grass that has 

 run to seed and been threshed, the stems of grasses that have 

 matured and withered in the pastures, fodder that has been 

 thoroughly washed out by heavy rains, sedges, reedgrass, rushes, 

 chaff, finely cut straw, and in the case of European sheep, the 

 fibrous tops of heather contribute to this affection. Lack of 

 water is one of the most potent factors, as an abundance of water 

 to float the ingesta is an essential condition of rumination. 

 Hence pasturage on dry hillsides, prairies or plains, apart from 

 streams, wells or ponds is especially dangerous unless water is 

 supplied artificially, and the winter season in our Northern states, 

 when the sources of drinking water are frozen over, and when 

 the chill of the liquid forbids its free consumption, is often 

 hurtful. 



Gerard attributes the affection to constant stabulation. This, 

 however, has a beneficial as well as a deleterious side. It under- 

 mines the health and vigor, and through lack of tone favors gas- 

 tric torpor and impaction, but it also secures ample leisure for 

 rumination, which is so essential to the integrity of the rumen 

 and favors the onward passage of its contents. With dry feeding 

 and a restricted water supply it cannot be too much condemned, 

 but with succulent food and abundance of water the alleged 

 danger is reduced to the minimum. 



Active work and over exertion of all kinds must be admitted 

 as a factor. At slow work the ox can still ruminate r but in rapid 

 work or under heavj' draft this is impossible, and the contained 

 liquids may pass over from rumen to manifolds conducing to im- 

 paction of the former, or fermentations may take place, swelling 

 up the mass of ingesta and distending the walls of the first 

 stomach. Similarly, cattle and sheep that are hurried off on a 



