TREATMENT OF URINARY CALCULI. 
359 
rectum generally reveals the stone as a firm, hard substance; in maies 
it can be directly felt by passing the finger through the urethra. 
Gravel is rarer in the horse, though cases are on record where large 
quantities have been removed by operation. 
Treatment. Internal medication is useless for dissolving the stone, 
and surgical removal alone can cure. Though it is certainly easier to 
remove a stone from the urethra than from the bladder, neither operation 
is easy nor unattended with danger, especially in carnivora; herbivora 
bear operation much better. 
Cutting for stone was first practised in man. In veterinary surgery it is 
said to have been introduced by Lafosse, who made the first experiment on a 
horse. Ercolani contends that even in the 14th century similar attempts had 
Fig. 159.— Calculus passed spon¬ 
taneously. Natural size. (Mr. 
McFarlane’s case.) 
Fig. 160. —Urethral obstruction removed by Mr. 
Mellis. Probably consisted of cystin. 
been made; but Bouley was probably the first to successfully employ the 
operation in the horse as a means of treatment. . 
Several methods formerly employed are now obsolete, such as cystotomia 
rectalis in which the urinary bladder was incised through the lower wall ot 
the rectum, and the stone removed through the rectum. Severe cystitis often 
resulted, and caused this method to be given up both m men and animals 
The bladder may also be reached through the lower portion of the 
abdominal wall, close in front of the os pubis, a method which m man has 
been called cystotomia suprapubica, or sectio alta, and is stiff used at the 
present day, but as in animals this necessitates opening the peritoneal cavity 
there is considerable danger of peritonitis, while the horizontal position of the 
bodv favours prolapse of bowel, and it is, of course, impossible to keep the 
animal continuously lying on the back. It is, therefore, necessary to resort 
to a third method, namely, section through the perineum (cystotomia permealis). 
Or as an alternative the urethra may be incised (urethrotomy) at one of various 
points in its course. 
Urethral calculi in the horse are only exceptionally found close behind 
the glans. When in this position, however, they may be removed without 
much difficulty or bleeding, by the operator standing on the left side of 
the animal, drawing the penis forward by means of a cloth, oi allowing 
an assistant to hold it, and then grasping the calculus with dressing or 
