140 DISEASES OF CATTLE. 



pure-water diuretics, and a daily dose of oil of turpentine in milk, or 

 a dose thi'ice a day of a solution containing one-tenth grain each of 

 biniodid of mercury and iodid 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 albumin or any other colloid (un- 

 crystallizable) body is strongly provocative of calculus, and should, 

 if possible, be corrected. Apart from cases from geological forma- 

 tion, faulty feeding, and other causes, the gi'and preventive of cal- 

 culus is a long, summer's pasturage of succulent grasses, or in winter 

 a diet of ensilage or other succulent feed. 



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 

 l^otash. 



STONE IN THE BLADDER (VESICAL CALCULUS, OR 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. 



Symptoms. — 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 

 driblets only, and the effect of such obstruction becomes manifest. 

 The point of obstruction is not always the same, but it is most fre- 

 quently 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 ver^^ 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 

 urina^) beneath the anus (PI. IX, fig. 2) may take place in a rhyth- 

 mical or pulsating manner. As a rule, however, no symptom is no-- 

 ticed for two days, only the animal is lacking in his usual spirits. By 

 this time the constantly accumulating urine has distended the blad- 



