114 DISEASES OF CATTLE. 



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

 able 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 disorders, 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, irrita- 

 tion, 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 formation 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 albumi- 

 noids 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 kidneys, the 

 formation of a deep-brown or reddish urine, and congestion of the 

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

 sugar — more than can be burned up in the circulation — overstimulates 

 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 nervous disorders. 

 Sprains of the loins will produce bleeding from the kidneys and dis- 

 ease of the spinal cord, and determine sometimes albuminous or 

 milky-looking urine. 



The kidney of the ox (PI. IX, fig. 1) is a compound organ made up 

 of fifteen to twenty-five separate lobules like so many separate kid- 

 neys, but all pouring their secretion into one common pouch (pelvis) 

 situated in an excavation in the center of the lower surface. While 



