210 PRACTICE OF EQUINE MEDICINE. 



How may the quantity of urine be altered ? 



The quantity may be increased (polyuria); diminished (fevers). 

 When the animal perspires freely the amount of urine is less, and 

 more when the skin is chilled. 



What variations in the color and odor may be noticed ? 



The color may be changed, being dark brown or black in 

 azoturia, smoky red or brown when it contains blood, milky when 

 it contains pus, greenish or reddish brown from the presence of bile. 

 In other cases, when the coloring matter is lessened, the urine is 

 lighter in color. 



The odor may be very strong, have the odor of ammonia or be 

 otherwise peculiar. 



What is the reaction of the urine of the horse ? 



The reaction of the urine of the horse varies with the kind of 

 food. It is usually alkaline, except in the suckling foal and an ani- 

 mal starving, when it becomes acid. 



In disease, a change is apt to occur, the reaction varying with 

 the individual case. 



How may the reaction be determined? 



To determine the reaction it must be done soon after the urine 

 is voided, as changes are apt to take place. 



If the reaction be alkaline, it is necessary to ascertain whether 

 it is " fixed " or " volatile." Hang a piece of red litmus paper, that 

 has been partly moistened with the urine, in the air to dry; if, when 

 dry, the blue color remains, then it is due to a fixed alkali (phos- 

 phates or carbonates); while if the red color returns, then a volatile 

 alkali (ammonia). 



Add hydrochloric acid in excess to the urine in a test-tube and 

 warm; if effervescence, the carbonates cause the alkalinity; if not, 

 the phosphates. 



What changes may occur in the specific gravity? 



The specific gravity may be altered, being high when the quan- 

 tity passed is diminished: in fevers, diabetes mellitus, when bile is 

 present, or when the solids are increased. 



It is low when the quantity is increased, as after large draughts 

 of water, in polyuria, when albumin is present, or when there is 

 deficiency in solids. 



