356 HEALTH AND DISEASE 



the whole. Vesical calculi in the horse are strikingly uniform in com- 

 position, and in this respect contrast greatly with similar formations in 

 omnivorous man, in whom they are also more frequent. In him the urine 

 contains a greater number and variety of crystallizable substances, several 

 of which, both separately and in combination with others, assume the form 

 of stone. Hence we have calculi of uric acid, urates of soda, ammonia, and 

 lime, as well as others of calcic acetate, triple phosphate, and various com- 

 binations of these renal salts. 



Symptoms of Stone. The symptoms attending the existence of 

 vesical calculus are far from uniform, either in their number, nature, or 

 intensity. In some cases they are few, slight, and dubious, while in 

 others they are many, pronounced, and easy of interpretation. The very 

 slight physiological disturbance sometimes seen in stone disease has, in 

 many instances, disarmed suspicion and frustrated detection, thus serving 

 to sustain the prevailing idea that stone in the bladder is a disease of 

 extreme rarity, a conclusion there is reason to think is too generally 

 accepted by veterinary practitioners. 



Vesical trouble arising out of the presence of stone is mostly exhibited, 

 in the first instance, by frequent attempts at staling, some of which are 

 abortive, and others more or less imperfectly and with difficulty accom- 

 plished. The urine is discharged in small quantities at brief intervals, and 

 the completion of the act is signalized by a deep grunt indicative of pain. 

 The desire to empty the bladder is more frequent and urgent during and 

 after exertion, and particularly marked when the pace has been quick. 

 Every now and again, while at work, the affected animal dwells in his move- 

 ment and essays to stop. If permitted to do so, the body is at once 

 extended, and a small quantity of urine discharged. Where the calculus is 

 large, rough on its surface, and free to move in the cavity of the bladder, 

 blood appears in the urine as the result of exertion. Whenever, therefore, 

 exertion is immediately followed by the appearance of blood in the urine, 

 the case should be regarded with suspicion, unless some other and more 

 obvious cause is revealed. In some instances the penis is projected from 

 the sheath, and again retracted, at short intervals, and we have seen it 

 remain extruded in a pendulous condition during the whole period of the 

 disease, and to return again only after the operation of lithotomy. 



The discharge of urine is sometimes effected in a continuous stream, 

 sometimes the flow is suddenly interrupted by the calculus blocking up the 

 neck of the bladder, and occasionally it passes away involuntarily in small 

 quantities. After the bladder has been freely emptied, the anus undergoes 

 a repetition of spasmodic contractions. Now and again the stone becomes 

 impacted in the neck of the bladder, or, if a small one. may escape into and 



