URINARY CALCULI. 
371 
in the bladder after death; Schell met with a collection of white earthy 
concretions weighing 13 drachms in the urinary bladder of an eighteen 
months pig that had always appeared healthy. 
(4.) URINARY CALCULI IN THE DOG. 
The urethral calculi not infrequent in old dogs are usually formed in 
the bladder. They almost always become fixed in the gutter of the os 
penis or close behind it. Straining to pass urine, passage of a few drops, 
uneasiness, distension of the bladder, &c., sufficiently indicate the nature 
of the condition. 
A metal catheter, which is easily introduced into the urethra, will at 
once reveal the presence of the calculus and its position. In this 
examination the dog is laid on its back, with its left side towards the 
operator. The prepuce, which should be grasped about an inch behind 
its termination, is then thrust back with the fore-finger and thumb 
behind the corona glandis, the latter firmly pressed upon, and the penis 
thus caused to protrude. The catheter is then introduced into the 
opening of the urethra, which is easily seen, and passed onwards until 
checked by contact with the calculus, readily recognised by its hardness. 
By now removing the left hand from the prepuce, the end of the catheter 
and the stone may at once be felt below the skin. 
In spite of this the operation offers greater difficulties than in other 
animals, is often followed by severe strictures, and not infrequently 
proves fatal. It has therefore been recommended, when possible, to 
thrust the stone back into the bladder, which may sometimes be effected 
with the help of an elastic catheter; but if, in consequence of the rough 
nature of the stone and the already existing swelling of the urethral 
mucous membrane, this prove impossible, early operation alone offers a 
chance of saving life, for rupture of the bladder in dogs leads to death 
in twenty-four to forty-eight hours, and is the more to be feared the more 
completely the passage of urine appears to be interfered with. 
Urethrotomy is carried out in dogs in the above described dorsal 
position. A catheter is passed into the urethra and held by an assistant; 
the skin is then incised for a length of § to 1J inches immediately over 
the stone, and a second incision made exposing the stone. The diffi¬ 
culties only begin at this point. As the gutter in the os penis is 
narrower below, and forms a kind of tube split along its inferior margin, 
it is often impossible to remove the stone, even when completely exposed. 
It is often necessary to employ a powerful but narrow pair of forceps, 
so as first to break down the calculus and then to remove the fragments 
from the swollen urethra, a proceeding often entailing injury to the 
latter. Several more calculi may be lodged behind the first and cause 
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