128 DISEASES OF CATTLE. 



men or between the thighs may be resorted to with success. Two 

 drams daily of copaiba or of solid extract of belladonna or 2 grains 

 Spanish flies may serve to restore the lost tone. These failing, the 

 use of electric currents may still prove successful. 



URINARY CALCULI (STONE, OR GRAVEL). 

 [PI. XI, figs. 1, 2, 3.] 



Stone, or gravel, consists in hard bodies mainly made up of the solid 

 earthy constituents of the urine which have crystallized out of that 

 liquid at some part of the urinary passage, and have remained as 

 small particles (gravel), or have concreted into large masses (stone, 

 calculus). In cattle it is no uncommon thing to find them distending 

 the practically microscopic tubes in the red substance of the kidney, 

 having been deposited from the urine in the solid form almost as soon 

 as that liquid has been separated from the blood. These stones appear 

 as white objects on the red ground formed by cutting sections of the 

 kidney, and are essentially products of the dry feed of winter, and 

 most common in working oxen, which are called upon to exhale more 

 water from the lungs and skins than are the slop-fed and inactive 

 cows. Little water being introduced into the body with the food, and 

 a considerable amount being expelled with the breath and perspira- 

 tion in connection with the active life, the urine becomes small in 

 amount, but having to carry out all waste material from the tissues 

 and the tissue-forming food, it becomes so charged with solids that it 

 is ready to deposit them on the slightest disturbance. If, therefore, 

 a little of the water of such concentrated urine is reabsorbed at any 

 point of the urinary passages, the remainder is no longer able to hold 

 the solids in solution, and they are at once precipitated in the solid 

 form as gravel or commencing stone. In cattle, on the other hand, 

 which are kept at pasture in summer, or which are fed liberally on 

 roots, potatoes, pumpkins, apples, or ensilage in winter, this concen- 

 trated condition of the urine is not induced, and under such circum- 

 stances, therefore, the formation of stone is practically unknown. 

 Nothing more need be said to show the controlling influence of dry 

 feeding in producing gravel and of a watery ration in preventing it. 

 Calculus in cattle is essentially a disease of winter, and of such cattle 

 as are denied succulent food and are confined to dry fodder as their 

 exclusive ration-. While there are exceptions, they are so rare that 

 they do not invalidate this general rule. It is true that stone in the kid- 

 ney or bladder is often found in the summer or in animals feeding at 

 the time on a more or less succulent ration, yet such masses usually date 

 .back to a former period when the animal was restricted to a dry ration. 

 In this connection it should be noted that a great drain of water 

 from the system by any other channel than the kidneys predisposes 

 to the production of gravel or stone. In case of profuse diarrhea, for 

 example, or of excessive secretion of milk, there is a corresponding 



