64 



as ascertained by blue litmus or red test papers. The horse on vege- 

 table 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 star- 

 vation or abstinence during disease) it is acid, turning blue litmus red. 

 (4) Organic constituents, as when glairy from albumen coagulableby 

 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 spontaneously, 

 or on boiling, or on the addition of chemical re-agents. 



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 fol- 

 lows: 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 dis- 

 solved it is albumen; if dissolved it was probably urate or hii)i)urate 

 of ammonia. Albumen 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, drop- 

 sies), in diseases of the heart and liver which prevent the free escape 

 of blood from the veins and throw back venous pressure on the kid- 

 neys, in inflammation of the lungs and jjleurpe, and even tympany 

 (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 ui), when treated with acetic acid, so that 

 each cell shows two or three nuclei. 



DIURESIS — POLYURIA — DIABETES INSIPIDUS — EXCESSIVE SECRETION 



OF URINE. 



This consists in an excessive secretion of a clear, watery urine of a 

 low speciflc gravity (1.007) with a correspondingly ardent thirst, a 

 rapidly advancing emaciation, and great loss of strength and spirit. 



Its causes may be any agent, medicinal, alimentary, or j)oisonous, 

 which unduly stimulates the kidneys; the reckless administration of 

 diuretics, which form such a common constituent of quack horse- 

 powders; acrid diuretic plants in grass or hay; new oats still imper- 

 fectly cured; an excess of roots or other very waterj^ food; a full 



