164 DISEASES OF CATTLE. 



its bacteria. In the latter direction plenty of pure water, diuretics, and 

 a daily dose of oil of turpentine in milk, or a dose thrice a day of a 

 solution containing one-tenth grain each of biniodide of mercury and 

 iodide of potassium would be indicated. 



In considering the subject of prevention it must never be forgotten 

 that any disease of a distant organ which determines the passage from 

 the blood into the urine of albumen or any other colloid (uncrystalliz- 

 able) body is strongly provocative of calculus, and should, if possible, 

 be corrected. Apart from cases due to geological formation, faulty 

 feeding, and other causes, the grand preventive of calculus is a long 

 summer's pasturage of succulent grasses, or in winter a diet of ensilage 

 or other succulent food. 



The calculi formed in part of silica demand special notice. This 

 agent is secreted in the urine in the form of silicate of potash and is 

 thrown down as insoluble silica when a stronger acid displaces it by 

 combining with the potash to its exclusion. In cases of siliceous calculi, 

 accordingly, the appropriate chemical prevention is caustic potash, 

 which being present in the free state would attract to itself any free 

 acid and leave the silica in its soluble condition as silicate of potash. 



STONE IN THE BLADDER VESICAL CALCULUS URETHRAL CALCULUS. 



Stone in the bladder may be of any size, but in the ox does not 

 usually exceed half an inch in diameter. There may, however, be a 

 number of small calculi; indeed, they are sometimes so small and 

 numerous as to form a small pulpy magma by which the bladder is 

 considerably distended. 



The symptoms of stone in the bladder may be absent until one of the 

 masses escapes into the urethra, but when this occurs the escape of 

 urine is prevented, or it is allowed to pass in drops or dribblets only, 

 and the effect of such obstruction becomes manifest. The point of 

 obstruction is not always the same, but it is most frequently at the 

 S-shaped curve of the penis, just above the testicles or scrotum. In 

 cows and heifers the urethra is so short and becomes so widely dilated 

 during the urination that the calculi easily escape in the flow of liquid 

 and dangerous symptoms practically never appear. 



Even in the male the signs of illness are at first very slight. A close 

 observer may notice the cylinders of hard earthy materials encircling 

 the tufts of hair at the opening of the prepuce. It may further be 

 observed that the stall remains dry and that the animal has not been 

 seen to pass water when out of doors. The tail may at times be gently 

 raised and contractions of the muscle (accelerator urinai) beneath the 

 anus (Plate ix, Fig. 2) may take place in a rythmical or pulsating man- 

 ner. But as a rule no symptom is noticed for a couple of days, only the 

 animal is lacking in his usual spirits. By this time the constantly 

 accumulating urine has distended the bladder beyond its power of 

 resistance and a rupture occurs, allowing the urine to escape into the 



