Obstruction of the urethra in rams is more commonly caused by deposits of gravel than by single large calculi. It is generally found in highly-fed animals, in which gravel accumulates and becomes massed together at some point in the canal, often near the free extremity, where it forms a plug, causing complete retention of urine. In other cases this retention is due to a mass of sediment formed by vesical mucus and fine gravel which collects about the neck of the bladder.
Three operations have been advised for the removal of this condition:—
(1.) Section of the Appendix of the Penis.—When the disease is just appearing the sedimentary material may be collected at the anterior extremity of the penis behind the appendix. The shepherds in such cases remove the extremity of the penis. The resistance disappears, the plug formed of gravel yields to the pressure of urine, and micturition occurs as usual. Excision of the appendix, however, incapacitates the ram for service.
(2.) Passage of the Catheter.—Passage of the catheter has been recommended for the removal of deposits of gravel in the urethra, but it seems a very questionable method.
Should it be determined on, the animal must be placed on its back. The penis is then withdrawn and the double S-shaped curve is obliterated. An incision is made over the canal behind the appendix and a soft gutta-percha sound is passed. The sabulous accumulation is thus dispersed.
(3.) Urethrotomy.—Scrotal urethrotomy may be performed as in the ox.
Fig. 307.—Passing the catheter in the cow.
Ischial urethrotomy is impracticable in very fat animals, but when the obstruction is about the neck of the bladder, and the animal’s condition admits of it, this operation may be performed.
The patient is fixed on its back, and a metallic or gutta-percha sound is passed into the urethra. The tissues are incised layer by layer in the direction of the sound. Once the urethra has been opened the soft magma may be washed out of the bladder by a free injection of boiled water or similar aseptic liquid.