DISEASES OF HORSES AND CATTLE. 113 



CHAPTER VII. 



DISEASES OF THE URINARY ORGANS. 



A short description of the kidneys is necessary 

 so that we may have a better idea of the causes and 

 nature of their diseases. The kidneys are two glan- 

 dular organs situated in the lumbar region of the 

 back. They are composed of a number of tubes 

 and tufts, around which the blood vessels run. The 

 supply of blood to the kidneys is very large for the 

 size of these organs. The tubes begin very small 

 at the surface of the kidney and are very numer- 

 ous; they soon join each other, becoming larger, 

 and finally terminate in a part of the kidney 

 termed the pelvis. At the lower border from this 

 place there is a small duct which leads to the blad- 

 der, through which the urine passes. The use of 

 the kidneys is to secrete the water and effete mat- 

 ters in the form of urine and uric acid, which would 

 soon poison the body if it remained there. The 

 blood vessels ramify around the tubes, and the 

 epithelium of the tubes secrete the urine from the 

 blood, and if we consider the quantity of urine 

 which is secreted daily, we need not wonder at the 

 size of the blood vessels which go to and from the 

 kidneys. If from want of action, from disease, or 

 otherwise the kidneys did not secrete this material 



