78 DISEASES OF THE HOESE. 



oncy, while on a green ration there is an abundant white deposit of 

 carbonate of lime. Of its morbid changes the following are to be 

 looked for: (1) Color: White from deposited salts of lime; brown or 

 red from blood clots or coloring matter; yellow or orange from bile 

 or blood pigment; pale from excess of water; or variously colored 

 from vegetable ingredients (santonin makes it red; rhubarb or senna, 

 brown; tar or carbolic acid, green). (2) Density: The horse's urine 

 may be 1.030 to 1.050, but it may greatly exceed this in diabetes and 

 may sink to 1.007 in diuresis. (3) Chemical reaction^ as ascertained 

 by blue litmus or red test papers. The horse on vegetable diet has 

 alkaline urine turning red test papers blue, while in the sucking colt 

 and the horse fed on flesh or on his own tissues (in starvation or ab- 

 stinence during disease) it is acid, turning blue litmus red. (4) 

 Organic constituents, as when glairy from albumen coagulable by 

 strong nitric acid and boiling, when charged with microscopic casts 

 of the uriniferous tubes, with the eggs or bodies of worms, with sugar, 

 blood, or bile. (5) In its salts, which may crystallize out spontane- 

 ously, or on boiling, or on the addition of chemical reagents. 



Albuminous urine in the horse is usually glairy, so that it may be 

 drawn out in threads, but its presence can always be tested as follows : 

 If the liquid is opaque, it may be first passed through filter paper; if 

 very dense and already precipitating its salts, it may be diluted with 

 distilled water ; add to the suspected liquid acetic acid drop by drop 

 until it reddens the blue litmus paper; then boil gently in a test tube; 

 if a precipitate is thrown down, set the tube aside to cool and then add 

 strong nitric acid. If the j^recipitate is not dissolved, it is albumen ; 

 if dissolved it was j^robably urate or hippurate of ammonia. Albu- 

 men is normally present in advanced gestation ; abnormally it is seen 

 in diseases in which there occurs destruction of blood globules 

 (anthrax, low fevers, watery states of the blood, dropsies), in diseases 

 of the heart and liver which prevent the free escape of blood from the 

 veins and throw back venous pressure on the kidneys, in inflamma- 

 tion of the lungs and pleura?, and even tympanj^ (bloating) , doubtless 

 from the same cause, and in all congestive or inflammatory diseases of 

 the kidneys, acute or chronic. 



Casts of the uriniferous tubes can only be seen by placing the sus- 

 pected urine under the microscope. They are usually very elastic 

 and mobile, waving about in the liquid when the cover-glass is 

 touched, and showing a uniform clear transparency (waxy) or entan- 

 gled circular epithelial cells or opaque granules or flattened red-blood 

 globules or clear refrangent oil globules. They may be even densely 

 opaque from crystals of earthy salts. 



Pus cells may be found in the urine associated with albumen, and 

 are recognized by clearing up, when treated with acetic acid, so that 

 each cell shows two or three nuclei. 



