458 SPORADIC DISEASES. 



ness, such as whisking of the tail, or even attempts to lie down, 

 or kicking at the belly with the hind feet. The mouth has 

 sometimes an acid or sour smell, the tongue is covered with a 

 whitish fur, and there is generally a degree of constipation or 

 irregular action of the bowels. An animal thus affected is stiff 

 in the loins, and is easily fatigued. 



Etiolocjij. — The causes are to be found in irregularity of feeding, 

 want of sufficient exercise, irregular exercise and work, such as 

 fatiguing journeys with long intervals of rest ; improper food; or 

 it may originate in weakened digestion from an unknown cause. 



Condition of the urine. — The urine at each emission is scanty; 

 of a pale amber colour ; clear, like pale sherry, and is neutral or 

 acid in its reaction. If examined immediately with the micro- 

 scope, crystals of the oxalates will most probably be detected. 

 In some instances, however, the crystals cannot be detected 

 with the microscope for a day or two after the urine has been 

 passed, the oxalic acid being present in its free state, and after- 

 wards combining with the lime and forming at least two dis- 

 tinctive forms of crystals: — 1,9^. and most common, Octahedra 

 {a) ; 2,d. Dumb-bell (h) (the dumb-bell is very rare in the horse). 

 — See fill. 27. 



Fig. 27. — Crystals of Oxalate of Lime, 

 (a. ) Octahedral form. (6.) Dumb-bell form. 



These crystals are soluble in nitric acid without effervescence, 

 are insoluble in water, and are unaltered by boiling in acetic 

 acid or liquor potassai. 



