112 THE MODERN HORSE DOCTOR. 



As it is a common custom to administer diuretics to horses 

 when the urine does not appear just about right, it may be well 

 for us to notice some of its variations : — 



" 1. In respect to age. In the foetus it is inodorous, insipid, and 

 almost aqueous ; but as the young grow, it becomes more acrid 

 and fetid, and in old age more particularly so. 



" 2. In respect to drink. The urine is secreted in greater quan- 

 tity, and of a more pale color, from cold and copious draughts. 



"3. In respect to food. From eating the heads of asparagus, 

 or olives, it contracts a peculiar smell ; from the fruit of the 

 opuntia it becomes red ; and from fasting, turbid. 



" 4. In respect to medicines. From the exhibition of rhubarb 

 root it becomes yellow; from cassia purple-green ; and from tur- 

 pentine it acquires a violet color. 



"5. In respect to the time of year. In the winter the urine is 

 more copious and aqueous ; but in the summer, from the increased 

 transpiration of the skin, it is more sparing, highly colored, and 

 so acrid that it sometimes occasions strangury. The climate 

 induces the same difference. 



" 6. In respect to muscular action of the body. The urine is 

 secreted more sparingly, and concentrated by motion ; and is 

 more copiously diluted and rendered crude by rest." 



From the above remarks, which to some extent apply to horses, 

 and from the result of experiments made on horses, we learn 

 that the urine is subject to great variations ; and therefore, should 

 it not appear natural, diuretics are not always indicated. 



It is generally supposed that diuretics act on the kidneys in a 

 much shorter time than other classes of medicines do on various 

 other parts of the animal economy. Magendie explains this on 

 the principle that diuretics, in the fluid form, " are directly ab- 

 sorbed by the veins, and transported by them to the liver and 

 heart, so that the direction which these liquids follow, in order to 

 reach the bladder, is much shorter than is generally admitted, 

 viz., by the lymphatic vessels, the mesenteric glands, and the 

 thoracic duct." We have said that simple treatment, light diet, 

 and rest will generally effect a cure of nephritis ; we must, how- 

 ever, have a curable case, and be permitted to attend to it in the 

 early stage, for cases of this kind sometimes terminate in degen- 



