OF VETERINARY MEDICINE. 209 



The prominent causes of urinary diseases may be summed up 

 as follows : 



All extensive inflammations and acute diseases attended by 

 fever diminish the liquids of the urine and increase the solids — 

 waste products — resulting in the irritation of the urinary organs 

 or the poisoning of the system at large by the retention of the 

 surplus waste. 



Diseases of the heart and lungs, by interfering with the free 

 onward flow of the blood from the right side of the heart, tend 

 to throw that liquid back upon the veins, and this backward 

 pressure of venous blood reacts upon the kidneys. 



Poisons in the food and water (such as irritant diuretic 

 plants, musty hay or oats), green vegetables covered with hoar 

 frost, excess of phosphates in such food as bran, peas, lentils, 

 vetches, rape cake, cotton-seed cake, etc., deprivation of water, 

 producing too great concentration of the body tissues, — these 

 are direct causes of disturbance in the kidneys. 



A disordered liver producing an excess of bile will color the 

 urine ; an excess of hippuric acid and its allied products favor 

 the formation of calcareous deposits ; of taurocholic acid, the 

 destruction of the blood elements and consequent irritation of the 

 kidneys ; of glycogen, the production of saccharine urine. 



Any disorder leading to impaired function of the stomach is 

 causative of an excess of hippuric acid, of bile, of oxalic acid, of 

 sugar, etc., in the urine, resulting in irritation of the urinary 

 passages. 



Diseases of the brain and nervous system, notably o.f the base 

 of the brain and the spinal cord, induce various urinary disorders, 

 such as chylous urine, diabetes, and albuminuria. 



In some cases the changes in the urine are the sole sign of 

 disease. In health the horse's urine is of a deep amber color 

 and has a strong odor. On a feed of grass it may show uniform 

 transparency, while on a grain and hay ration there is an abundant 

 white deposit of carbonate of lime. Of the morbid changes the 

 following are to be looked for: (I) Color; white from deposited 

 salts of lime ; brown or red from blood clots or coloring matter ; 

 yellow or orange from bile or from blood pigment ; pale from 

 excess o^ water; or variously from vegetable ingredients 



