DISEASES OF THE URINARY ORGANS. 225 



of irritation which proceeds from intestinal calculi, the surfaces of 

 which are always rough. 



Mr. YouATT says that " the symptoms of ptone in the bladder 

 much resemble tliose of spasmodic colic, except that, on careful 

 inquiry, it will be found that there has been much irregularity in 

 the discharge of urine, and occasional suppression of it. When 

 fits of apparent colic frequently return, and are accompanied by 

 any peculiarity in the appearance or the discharge of the urine, the 

 horse should be carefully examined. For this purpose, he must 

 be thrown. If there is stone in the bladder, it will, while the 

 horse lies on his back, press on the rectum. Several cases have 

 lately occurred of successful extraction of the calculus, but to 

 effect this it is always necessary to have recourse to the aid of a 

 veterinary practitioner." 



It is not necessary to cast the hors« in view of ascertaining the 

 presence of calculus. The hand can be introduced into the rectum 

 while the horse is standing. The rectum should, however, first be 

 evacuated by enemas of warm water. But we have a better plan 

 than this. A sound or jointed catheter has been invented, which, 

 when pa?sed into the bladder, determines, by percussion, the pres- 

 ence of calculi. The operation of lithotomy can only be performed 

 by one skilled in the science ; yet the reader may desire to know 

 something about the mode of performing it ; therefore I introduce 

 a case of the kind, which occurred in the practice of Mr. Field. 

 The following is the case : 



" The animal was cast, in the usual manner, and both hind 

 legs were drawn to the shoulders, as if for castration. Eead's new 

 flexible catheter being passed into the bladder, a quantity of warm 

 water was injected sufficient to distend that organ and the urethra 

 moderately. The catheter being withdrawn, and holding the penis 

 with the left hand, a slightly-curved grooved staff, two feet long, 

 was introduced, so as for the curved part to come into the subanal 

 portion of the urethra, above the posterior edge of the iscliium, 

 extending toward the sphincter ani. An assistant, kneeling on 

 the left side of the horse, drew the penis forward with his left 

 hand, and gently pushed the staff backward with the right, at the 

 same time keeping the groove exactly beneath the raphe. This 

 elevated the portion of the urethra to be incised. I then made an 

 incision a line from and on the right side of the raphe, through 

 the skin and fascia, extending the length of from three to four 

 15 



