116 DISEASES OF CATTLE. 



passing mostly from the lungs, and to a slight extent by the bowels. 

 The skin of the ox does not perspire so readily nor so freely as that 

 of the horse; hence the kidneys and lungs are called upon for e.\tra 

 work. The influence of an excess of water in the food is most re- 

 markable in swill-fed distillery cattle, which urinate profusely at 

 frequent intervals and yet thrive and fatten rapidly. 



Among the other conditions that increase the flow of urine is over- 

 filling of (internal pressure in) the blood vessels of the kidneys. 

 Hence the contraction of the blood vessels of the skin by cold drives 

 the blood inward, tends to dilate the blood vessels of the kidneys, 

 and to increase the secretion of urine. Nervous disorder's, such as 

 excitement, fear, congestions, or structural injuries to the back part 

 of the base of the brain have a similar result. Hence, doubtless, the 

 action of certain fungi growing in musty hay or oats in producing 

 profuse flow of urine, whereas other forms of musty fodder cause 

 stupor^ delirium, or paralysis. Bacteria and their products are 

 mainly expelled by the kidneys, and become sources of local infection, 

 irritation, and disease. 



The amount of urine passed daily by an ox on dry feeding averages 

 7 to 12 pints, but this may be increased enormously on a watery diet. 



The mutual influence of the kidneys and other important organs 

 tends to explain the way in which disease in one part supervenes on 

 preexisting disorder in another. The introduction of albuminoids in 

 excess into the blood means the fonnation of an excess of urea, and a 

 more profuse secretion of urine, of a higher specific gravity, and 

 with a greater tendency to deposit its solid constituents, as gravel, in 

 the kidneys or bladder. A torpid action of the liver, leaving the 

 albuminoids in transition forms, less soluble than the urea into which 

 they should have been changed^ favors the onset of rheumatism or 

 nervous disorder, the deposit of such albuminoid products in the kid- 

 neys, the formation of a de«p-brown or reddish urine, and congestion 

 of the kidneys. Any abnonnal activity of the liver in the production 

 of sugar — more than can be burned up in the circulation — over- 

 stinralates the kidneys and produces increased flow of a heavy urine 

 with a sweetish taste. This increased production of sugar may be 

 primarily due to disease of the brain, which, in its turn, determines 

 the disorder of the liver. Disease of the right side of the heart or of 

 the lungs, by obstructing the onward flow of blood from the veins, 

 increases the blood pressure in the kidneys and produces disorder 

 and excessive secretion. Inactivity of the kidneys determines an 

 increase in the blood of waste products, which become irritating to 

 different parts, producing skin eruptions, itching^ dropsies, and nerv- 

 ous disorders. Sprains of the loins will produce bleeding from the 

 kidneys and disease of the spinal cord, and determine sometimes 

 albuminous or milky-looking urine. 



