The urethra can be incised by one of three methods.
The animal should be secured, if possible, in the standing position.
The first method, which dates back to very early times, consists in puncturing the urethra at one stroke with the fleam or lancet, and opening it more freely, after introducing a grooved director. This method is very useful where rupture of the bladder is imminent.
The extraction of a calculus fixed in the ischial region, or the manipulation of an obstruction at any other point, can afterwards be undertaken.
Second method. A second method consists in incising the subcutaneous tissues, layer by layer, until the urethra is reached at the ischial arch.
The operation is terminated by puncturing the urethra and enlarging the incision in an upward direction after passing a grooved director. This method minimises hæmorrhage and urinary infiltration. By previously injecting cocaine, the operation may be made practically painless.
Third method. Puncture of the urethra by a single stroke with a straight bistoury at the ischial arch.
The opening is enlarged in an upward direction with the same instrument.
SCROTAL URETHROTOMY.
Scrotal urethrotomy is necessary when the calculus is situated in one of the S-shaped curves of the penis or nearer the glans.