?10 THEORY AND PRACTICE 



(santonin makes it red; rhubarb or senna, brown; methylene 

 blue, tar or carbolic acid, green). (2) Density: The 

 horse's urine may be 1.030 to 1.050, but the specific gravity may 

 exceed this, as in diabetes, or it may sink to 1.007, as in diuresis. 

 (3) Chemical reaction: The horse on a vegetable diet has alkaline 

 iirine, while in the sucking colt or in a horse fed on flesh or on 

 his own tissues, as in starvation or abstinence during disease, the 

 urine is acid. (4) Organic constituents: Albumen, mucous shreds, 

 casts, worms, etc. (5) Salts: These crystalize out spontaneously 

 as the result of excess of some acid or base in the urine. Pus 

 and an excess of mucous are frequently found in the urine . 



ALBUMINURIA. 



In the horse this can be safely called equine Bright's. It 

 occurs in two forms, acute and chronic. It is mostly due to indi- 

 gestion. The chief symptom is the presence of albumin in the 

 urine, but sometimes none may be present. Accordingly, several 

 tests should be made for the determination of the albumin. You 

 cannot rely on a single sample. Tube casts are also present. 

 These are cylinders of fibrous coagulum, the coagulation having 

 taken place in the uriniferous tubules to wdiich the casts conform 

 in shape. In the case of fatty degeneration the casts will have 

 a waxy appearance, due to the presence of fat and oil in them. 



Tests for Albumin in the Urine. — Put some of the urine in a 

 test-tube and boil it : if any albumin is present, a white coagulum 

 will form. Heating the urine will also precipitate phosphates if 

 in excess, but nitric acid will dissolve them. If the urine is 

 strongly alkaline, neutralize it with a little acetic acid, for alka- 

 line urine may coagulate when heated even though albumin is 

 not present. Another test consists in placing a little urine in a 

 test-tube and carefully pouring down the side of the tube a little 

 strong nitric acid — pour it in such a way that it goes to the 

 bottom of the tube underneath the urine and a white line of coag- 

 ulation will form between the acid and the urine. 



Semeiology. — The first indication of equine Bright's is stifif- 

 ness in the gait of the horse — of the hind parts. In old con- 

 firmed cases they step about eight or ten inches to a step, are stifif 



